From e8a18e3f00f3ee8d07c17ab1ea3ad4df4a3b6fe0 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Fri, 21 Oct 2022 07:44:49 +0200 Subject: parisc: Make 8250_gsc driver dependend on CONFIG_PARISC Although the name of the driver 8250_gsc.c suggests that it handles only serial ports on the GSC bus, it does handle serial ports listed in the parisc machine inventory as well, e.g. the serial ports in a C8000 PCI-only workstation. Change the dependency to CONFIG_PARISC, so that the driver gets included in the kernel even if CONFIG_GSC isn't set. Reported-by: Mikulas Patocka Cc: Signed-off-by: Helge Deller --- drivers/tty/serial/8250/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index d0b49e15fbf5..7b3ffb7f50ab 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -118,7 +118,7 @@ config SERIAL_8250_CONSOLE config SERIAL_8250_GSC tristate - depends on SERIAL_8250 && GSC + depends on SERIAL_8250 && PARISC default SERIAL_8250 config SERIAL_8250_DMA -- cgit v1.2.3 From 9e4e2ce1a78ed92ed91135e90c85f27d75388129 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Fri, 21 Oct 2022 08:02:31 +0200 Subject: parisc/serial: Rename 8250_gsc.c to 8250_parisc.c The file name of this driver is misleading - it handles various serial ports on parisc machines, not just such on the GSC bus. Rename the file to make this clearer. Suggested-by: Mikulas Patocka Signed-off-by: Helge Deller --- drivers/tty/serial/8250/8250_gsc.c | 130 ---------------------------------- drivers/tty/serial/8250/8250_parisc.c | 130 ++++++++++++++++++++++++++++++++++ drivers/tty/serial/8250/Kconfig | 2 +- drivers/tty/serial/8250/Makefile | 2 +- 4 files changed, 132 insertions(+), 132 deletions(-) delete mode 100644 drivers/tty/serial/8250/8250_gsc.c create mode 100644 drivers/tty/serial/8250/8250_parisc.c (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_gsc.c b/drivers/tty/serial/8250/8250_gsc.c deleted file mode 100644 index 948d0a1c6ae8..000000000000 --- a/drivers/tty/serial/8250/8250_gsc.c +++ /dev/null @@ -1,130 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0+ -/* - * Serial Device Initialisation for Lasi/Asp/Wax/Dino - * - * (c) Copyright Matthew Wilcox 2001-2002 - */ - -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#include "8250.h" - -static int __init serial_init_chip(struct parisc_device *dev) -{ - struct uart_8250_port uart; - unsigned long address; - int err; - -#if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC) - if (!dev->irq && (dev->id.sversion == 0xad)) - dev->irq = iosapic_serial_irq(dev); -#endif - - if (!dev->irq) { - /* We find some unattached serial ports by walking native - * busses. These should be silently ignored. Otherwise, - * what we have here is a missing parent device, so tell - * the user what they're missing. - */ - if (parisc_parent(dev)->id.hw_type != HPHW_IOA) - dev_info(&dev->dev, - "Serial: device 0x%llx not configured.\n" - "Enable support for Wax, Lasi, Asp or Dino.\n", - (unsigned long long)dev->hpa.start); - return -ENODEV; - } - - address = dev->hpa.start; - if (dev->id.sversion != 0x8d) - address += 0x800; - - memset(&uart, 0, sizeof(uart)); - uart.port.iotype = UPIO_MEM; - /* 7.272727MHz on Lasi. Assumed the same for Dino, Wax and Timi. */ - uart.port.uartclk = (dev->id.sversion != 0xad) ? - 7272727 : 1843200; - uart.port.mapbase = address; - uart.port.membase = ioremap(address, 16); - if (!uart.port.membase) { - dev_warn(&dev->dev, "Failed to map memory\n"); - return -ENOMEM; - } - uart.port.irq = dev->irq; - uart.port.flags = UPF_BOOT_AUTOCONF; - uart.port.dev = &dev->dev; - - err = serial8250_register_8250_port(&uart); - if (err < 0) { - dev_warn(&dev->dev, - "serial8250_register_8250_port returned error %d\n", - err); - iounmap(uart.port.membase); - return err; - } - - return 0; -} - -static const struct parisc_device_id serial_tbl[] __initconst = { - { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00075 }, - { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008c }, - { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008d }, - { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x000ad }, - { 0 } -}; - -/* Hack. Some machines have SERIAL_0 attached to Lasi and SERIAL_1 - * attached to Dino. Unfortunately, Dino appears before Lasi in the device - * tree. To ensure that ttyS0 == SERIAL_0, we register two drivers; one - * which only knows about Lasi and then a second which will find all the - * other serial ports. HPUX ignores this problem. - */ -static const struct parisc_device_id lasi_tbl[] __initconst = { - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03B, 0x0008C }, /* C1xx/C1xxL */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03C, 0x0008C }, /* B132L */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03D, 0x0008C }, /* B160L */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03E, 0x0008C }, /* B132L+ */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03F, 0x0008C }, /* B180L+ */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x046, 0x0008C }, /* Rocky2 120 */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x047, 0x0008C }, /* Rocky2 150 */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x04E, 0x0008C }, /* Kiji L2 132 */ - { HPHW_FIO, HVERSION_REV_ANY_ID, 0x056, 0x0008C }, /* Raven+ */ - { 0 } -}; - - -MODULE_DEVICE_TABLE(parisc, serial_tbl); - -static struct parisc_driver lasi_driver __refdata = { - .name = "serial_1", - .id_table = lasi_tbl, - .probe = serial_init_chip, -}; - -static struct parisc_driver serial_driver __refdata = { - .name = "serial", - .id_table = serial_tbl, - .probe = serial_init_chip, -}; - -static int __init probe_serial_gsc(void) -{ - register_parisc_driver(&lasi_driver); - register_parisc_driver(&serial_driver); - return 0; -} - -module_init(probe_serial_gsc); - -MODULE_LICENSE("GPL"); diff --git a/drivers/tty/serial/8250/8250_parisc.c b/drivers/tty/serial/8250/8250_parisc.c new file mode 100644 index 000000000000..948d0a1c6ae8 --- /dev/null +++ b/drivers/tty/serial/8250/8250_parisc.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Serial Device Initialisation for Lasi/Asp/Wax/Dino + * + * (c) Copyright Matthew Wilcox 2001-2002 + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "8250.h" + +static int __init serial_init_chip(struct parisc_device *dev) +{ + struct uart_8250_port uart; + unsigned long address; + int err; + +#if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC) + if (!dev->irq && (dev->id.sversion == 0xad)) + dev->irq = iosapic_serial_irq(dev); +#endif + + if (!dev->irq) { + /* We find some unattached serial ports by walking native + * busses. These should be silently ignored. Otherwise, + * what we have here is a missing parent device, so tell + * the user what they're missing. + */ + if (parisc_parent(dev)->id.hw_type != HPHW_IOA) + dev_info(&dev->dev, + "Serial: device 0x%llx not configured.\n" + "Enable support for Wax, Lasi, Asp or Dino.\n", + (unsigned long long)dev->hpa.start); + return -ENODEV; + } + + address = dev->hpa.start; + if (dev->id.sversion != 0x8d) + address += 0x800; + + memset(&uart, 0, sizeof(uart)); + uart.port.iotype = UPIO_MEM; + /* 7.272727MHz on Lasi. Assumed the same for Dino, Wax and Timi. */ + uart.port.uartclk = (dev->id.sversion != 0xad) ? + 7272727 : 1843200; + uart.port.mapbase = address; + uart.port.membase = ioremap(address, 16); + if (!uart.port.membase) { + dev_warn(&dev->dev, "Failed to map memory\n"); + return -ENOMEM; + } + uart.port.irq = dev->irq; + uart.port.flags = UPF_BOOT_AUTOCONF; + uart.port.dev = &dev->dev; + + err = serial8250_register_8250_port(&uart); + if (err < 0) { + dev_warn(&dev->dev, + "serial8250_register_8250_port returned error %d\n", + err); + iounmap(uart.port.membase); + return err; + } + + return 0; +} + +static const struct parisc_device_id serial_tbl[] __initconst = { + { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x00075 }, + { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008c }, + { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x0008d }, + { HPHW_FIO, HVERSION_REV_ANY_ID, HVERSION_ANY_ID, 0x000ad }, + { 0 } +}; + +/* Hack. Some machines have SERIAL_0 attached to Lasi and SERIAL_1 + * attached to Dino. Unfortunately, Dino appears before Lasi in the device + * tree. To ensure that ttyS0 == SERIAL_0, we register two drivers; one + * which only knows about Lasi and then a second which will find all the + * other serial ports. HPUX ignores this problem. + */ +static const struct parisc_device_id lasi_tbl[] __initconst = { + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03B, 0x0008C }, /* C1xx/C1xxL */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03C, 0x0008C }, /* B132L */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03D, 0x0008C }, /* B160L */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03E, 0x0008C }, /* B132L+ */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x03F, 0x0008C }, /* B180L+ */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x046, 0x0008C }, /* Rocky2 120 */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x047, 0x0008C }, /* Rocky2 150 */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x04E, 0x0008C }, /* Kiji L2 132 */ + { HPHW_FIO, HVERSION_REV_ANY_ID, 0x056, 0x0008C }, /* Raven+ */ + { 0 } +}; + + +MODULE_DEVICE_TABLE(parisc, serial_tbl); + +static struct parisc_driver lasi_driver __refdata = { + .name = "serial_1", + .id_table = lasi_tbl, + .probe = serial_init_chip, +}; + +static struct parisc_driver serial_driver __refdata = { + .name = "serial", + .id_table = serial_tbl, + .probe = serial_init_chip, +}; + +static int __init probe_serial_gsc(void) +{ + register_parisc_driver(&lasi_driver); + register_parisc_driver(&serial_driver); + return 0; +} + +module_init(probe_serial_gsc); + +MODULE_LICENSE("GPL"); diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index 7b3ffb7f50ab..b0f62345bc84 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -116,7 +116,7 @@ config SERIAL_8250_CONSOLE If unsure, say N. -config SERIAL_8250_GSC +config SERIAL_8250_PARISC tristate depends on SERIAL_8250 && PARISC default SERIAL_8250 diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index bee908f99ea0..1615bfdde2a0 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -12,7 +12,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250.o 8250_base.o 8250_base-$(CONFIG_SERIAL_8250_DMA) += 8250_dma.o 8250_base-$(CONFIG_SERIAL_8250_DWLIB) += 8250_dwlib.o 8250_base-$(CONFIG_SERIAL_8250_FINTEK) += 8250_fintek.o -obj-$(CONFIG_SERIAL_8250_GSC) += 8250_gsc.o +obj-$(CONFIG_SERIAL_8250_PARISC) += 8250_parisc.o obj-$(CONFIG_SERIAL_8250_PCI) += 8250_pci.o obj-$(CONFIG_SERIAL_8250_EXAR) += 8250_exar.o obj-$(CONFIG_SERIAL_8250_HP300) += 8250_hp300.o -- cgit v1.2.3 From 038ee49fef18710bedd38b531d173ccd746b2d8d Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Tue, 27 Sep 2022 13:52:34 +0200 Subject: serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios() RS485-enabled UART ports on TI Sitara SoCs with active-low polarity exhibit a Transmit Enable glitch on ->set_termios(): omap8250_restore_regs(), which is called from omap_8250_set_termios(), sets the TCRTLR bit in the MCR register and clears all other bits, including RTS. If RTS uses active-low polarity, it is now asserted for no reason. The TCRTLR bit is subsequently cleared by writing up->mcr to the MCR register. That variable is always zero, so the RTS bit is still cleared (incorrectly so if RTS is active-high). (up->mcr is not, as one might think, a cache of the MCR register's current value. Rather, it only caches a single bit of that register, the AFE bit. And it only does so if the UART supports the AFE bit, which OMAP does not. For details see serial8250_do_set_termios() and serial8250_do_set_mctrl().) Finally at the end of omap8250_restore_regs(), the MCR register is restored (and RTS deasserted) by a call to up->port.ops->set_mctrl() (which equals serial8250_set_mctrl()) and serial8250_em485_stop_tx(). So there's an RTS glitch between setting TCRTLR and calling serial8250_em485_stop_tx(). Avoid by using a read-modify-write when setting TCRTLR. While at it, drop a redundant initialization of up->mcr. As explained above, the variable isn't used by the driver and it is already initialized to zero because it is part of the static struct serial8250_ports[] declared in 8250_core.c. (Static structs are initialized to zero per section 6.7.8 nr. 10 of the C99 standard.) Cc: Jan Kiszka Cc: Su Bao Cheng Tested-by: Matthias Schiffer Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/6554b0241a2c7fd50f32576fdbafed96709e11e8.1664278942.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 41b8c6b27136..68f5a167377f 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -292,6 +292,7 @@ static void omap8250_restore_regs(struct uart_8250_port *up) { struct omap8250_priv *priv = up->port.private_data; struct uart_8250_dma *dma = up->dma; + u8 mcr = serial8250_in_MCR(up); if (dma && dma->tx_running) { /* @@ -308,7 +309,7 @@ static void omap8250_restore_regs(struct uart_8250_port *up) serial_out(up, UART_EFR, UART_EFR_ECB); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A); - serial8250_out_MCR(up, UART_MCR_TCRTLR); + serial8250_out_MCR(up, mcr | UART_MCR_TCRTLR); serial_out(up, UART_FCR, up->fcr); omap8250_update_scr(up, priv); @@ -324,7 +325,8 @@ static void omap8250_restore_regs(struct uart_8250_port *up) serial_out(up, UART_LCR, 0); /* drop TCR + TLR access, we setup XON/XOFF later */ - serial8250_out_MCR(up, up->mcr); + serial8250_out_MCR(up, mcr); + serial_out(up, UART_IER, up->ier); serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); @@ -669,7 +671,6 @@ static int omap_8250_startup(struct uart_port *port) pm_runtime_get_sync(port->dev); - up->mcr = 0; serial_out(up, UART_FCR, UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); serial_out(up, UART_LCR, UART_LCR_WLEN8); -- cgit v1.2.3 From 93810191f5d23652c0b8a1a9b3a4a89d6fd5063e Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Mon, 24 Oct 2022 09:36:13 +0300 Subject: serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl() There are cases where omap8250_set_mctrl() may get called after the UART has already autoidled causing an asynchronous external abort. This can happen on ttyport_open(): mem_serial_in from omap8250_set_mctrl+0x38/0xa0 omap8250_set_mctrl from uart_update_mctrl+0x4c/0x58 uart_update_mctrl from uart_dtr_rts+0x60/0xa8 uart_dtr_rts from tty_port_block_til_ready+0xd0/0x2a8 tty_port_block_til_ready from uart_open+0x14/0x1c uart_open from ttyport_open+0x64/0x148 And on ttyport_close(): omap8250_set_mctrl from uart_update_mctrl+0x3c/0x48 uart_update_mctrl from uart_dtr_rts+0x54/0x9c uart_dtr_rts from tty_port_shutdown+0x78/0x9c tty_port_shutdown from tty_port_close+0x3c/0x74 tty_port_close from ttyport_close+0x40/0x58 It can also happen on disassociate_ctty() calling uart_shutdown() that ends up calling omap8250_set_mctrl(). Let's fix the issue by adding missing PM runtime calls to omap8250_set_mctrl(). To do this, we need to add __omap8250_set_mctrl() that can be called from both omap8250_set_mctrl(), and from runtime PM resume path when restoring the registers. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reported-by: Merlijn Wajer Reported-by: Romain Naour Reported-by: Ivaylo Dimitrov Tested-by: Ivaylo Dimitrov Signed-off-by: Tony Lindgren Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221024063613.25943-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 68f5a167377f..7bfa87094125 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -157,7 +157,11 @@ static u32 uart_read(struct uart_8250_port *up, u32 reg) return readl(up->port.membase + (reg << up->port.regshift)); } -static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) +/* + * Called on runtime PM resume path from omap8250_restore_regs(), and + * omap8250_set_mctrl(). + */ +static void __omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct uart_8250_port *up = up_to_u8250p(port); struct omap8250_priv *priv = up->port.private_data; @@ -181,6 +185,20 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) } } +static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + int err; + + err = pm_runtime_resume_and_get(port->dev); + if (err) + return; + + __omap8250_set_mctrl(port, mctrl); + + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); +} + /* * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460) * The access to uart register after MDR1 Access @@ -343,7 +361,7 @@ static void omap8250_restore_regs(struct uart_8250_port *up) omap8250_update_mdr1(up, priv); - up->port.ops->set_mctrl(&up->port, up->port.mctrl); + __omap8250_set_mctrl(&up->port, up->port.mctrl); if (up->port.rs485.flags & SER_RS485_ENABLED) serial8250_em485_stop_tx(up); -- cgit v1.2.3 From e828e56684d61b17317e0cfdef83791fa61cb76b Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Thu, 13 Oct 2022 13:23:39 +0200 Subject: serial: 8250_omap: remove wait loop from Errata i202 workaround MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We were occasionally seeing the "Errata i202: timedout" on an AM335x board when repeatedly opening and closing a UART connected to an active sender. As new input may arrive at any time, it is possible to miss the "RX FIFO empty" condition, forcing the loop to wait until it times out. Nothing in the i202 Advisory states that such a wait is even necessary; other FIFO clear functions like serial8250_clear_fifos() do not wait either. For this reason, it seems safe to remove the wait, fixing the mentioned issue. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reviewed-by: Ilpo Järvinen Signed-off-by: Matthias Schiffer Link: https://lore.kernel.org/r/20221013112339.2540767-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 17 ----------------- 1 file changed, 17 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 7bfa87094125..766c57d50b4c 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -211,27 +211,10 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl) static void omap_8250_mdr1_errataset(struct uart_8250_port *up, struct omap8250_priv *priv) { - u8 timeout = 255; - serial_out(up, UART_OMAP_MDR1, priv->mdr1); udelay(2); serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR); - /* - * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and - * TX_FIFO_E bit is 1. - */ - while (UART_LSR_THRE != (serial_in(up, UART_LSR) & - (UART_LSR_THRE | UART_LSR_DR))) { - timeout--; - if (!timeout) { - /* Should *never* happen. we warn and carry on */ - dev_crit(up->port.dev, "Errata i202: timedout %x\n", - serial_in(up, UART_LSR)); - break; - } - udelay(1); - } } static void omap_8250_get_divisor(struct uart_port *port, unsigned int baud, -- cgit v1.2.3 From e3f0c638f428fd66b5871154b62706772045f91a Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Fri, 28 Oct 2022 13:58:13 +0300 Subject: serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove() On remove, we get an error for "Runtime PM usage count underflow!". I guess this driver is mostly built-in, and this issue has gone unnoticed for a while. Somehow I did not catch this issue with my earlier fix done with commit 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime"). Fixes: 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime") Signed-off-by: Tony Lindgren Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221028105813.54290-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 766c57d50b4c..c6ec6eb7ee21 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1460,6 +1460,11 @@ err: static int omap8250_remove(struct platform_device *pdev) { struct omap8250_priv *priv = platform_get_drvdata(pdev); + int err; + + err = pm_runtime_resume_and_get(&pdev->dev); + if (err) + return err; pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); -- cgit v1.2.3 From d0b68629bd2fb61e0171a62f2e8da3db322f5cf6 Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Fri, 28 Oct 2022 14:00:44 +0300 Subject: serial: 8250: omap: Flush PM QOS work on remove Rebinding 8250_omap in a loop will at some point produce a warning for kernel/power/qos.c:296 cpu_latency_qos_update_request() with error "cpu_latency_qos_update_request called for unknown object". Let's flush the possibly pending PM QOS work scheduled from omap8250_runtime_suspend() before we disable runtime PM. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index c6ec6eb7ee21..3f33014022f0 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -1468,6 +1468,7 @@ static int omap8250_remove(struct platform_device *pdev) pm_runtime_dont_use_autosuspend(&pdev->dev); pm_runtime_put_sync(&pdev->dev); + flush_work(&priv->qos_work); pm_runtime_disable(&pdev->dev); serial8250_unregister_port(priv->line); cpu_latency_qos_remove_request(&priv->pm_qos_request); -- cgit v1.2.3 From a931237cbea256aff13bb403da13a97b2d1605d9 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Tue, 8 Nov 2022 14:19:49 +0200 Subject: serial: 8250: Fall back to non-DMA Rx if IIR_RDI occurs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit DW UART sometimes triggers IIR_RDI during DMA Rx when IIR_RX_TIMEOUT should have been triggered instead. Since IIR_RDI has higher priority than IIR_RX_TIMEOUT, this causes the Rx to hang into interrupt loop. The problem seems to occur at least with some combinations of small-sized transfers (I've reproduced the problem on Elkhart Lake PSE UARTs). If there's already an on-going Rx DMA and IIR_RDI triggers, fall graciously back to non-DMA Rx. That is, behave as if IIR_RX_TIMEOUT had occurred. 8250_omap already considers IIR_RDI similar to this change so its nothing unheard of. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: Co-developed-by: Srikanth Thokala Signed-off-by: Srikanth Thokala Co-developed-by: Aman Kumar Signed-off-by: Aman Kumar Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index fe8662cd9402..92dd18716169 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1897,6 +1897,10 @@ EXPORT_SYMBOL_GPL(serial8250_modem_status); static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) { switch (iir & 0x3f) { + case UART_IIR_RDI: + if (!up->dma->rx_running) + break; + fallthrough; case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); fallthrough; -- cgit v1.2.3 From 1bfcbe5805d0cfc83c3544dcd01e0a282c1f6790 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Tue, 8 Nov 2022 14:19:50 +0200 Subject: serial: 8250_lpss: Configure DMA also w/o DMA filter MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the platform doesn't use DMA device filter (as is the case with Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This results in skipping also *_maxburst setup which is undesirable. Refactor lpss8250_dma_setup() to configure DMA even if filter is not setup. Cc: stable Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_lpss.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 44cc755b1a29..7d9cddbfef40 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -277,8 +277,13 @@ static int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port struct dw_dma_slave *rx_param, *tx_param; struct device *dev = port->port.dev; - if (!lpss->dma_param.dma_dev) + if (!lpss->dma_param.dma_dev) { + dma = port->dma; + if (dma) + goto out_configuration_only; + return 0; + } rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL); if (!rx_param) @@ -289,16 +294,18 @@ static int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port return -ENOMEM; *rx_param = lpss->dma_param; - dma->rxconf.src_maxburst = lpss->dma_maxburst; - *tx_param = lpss->dma_param; - dma->txconf.dst_maxburst = lpss->dma_maxburst; dma->fn = lpss8250_dma_filter; dma->rx_param = rx_param; dma->tx_param = tx_param; port->dma = dma; + +out_configuration_only: + dma->rxconf.src_maxburst = lpss->dma_maxburst; + dma->txconf.dst_maxburst = lpss->dma_maxburst; + return 0; } -- cgit v1.2.3 From 7090abd6ad0610a144523ce4ffcb8560909bf2a8 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Tue, 8 Nov 2022 14:19:51 +0200 Subject: serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Configure DMA to use 16B burst size with Elkhart Lake. This makes the bus use more efficient and works around an issue which occurs with the previously used 1B. The fix was initially developed by Srikanth Thokala and Aman Kumar. This together with the previous config change is the cleaned up version of the original fix. Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_lpss.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index 7d9cddbfef40..0e43bdfb7459 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -174,6 +174,8 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port) */ up->dma = dma; + lpss->dma_maxburst = 16; + port->set_termios = dw8250_do_set_termios; return 0; -- cgit v1.2.3 From 1980860e0c8299316cddaf0992dd9e1258ec9d88 Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Tue, 8 Nov 2022 14:19:52 +0200 Subject: serial: 8250: Flush DMA Rx on RLSI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Returning true from handle_rx_dma() without flushing DMA first creates a data ordering hazard. If DMA Rx has handled any character at the point when RLSI occurs, the non-DMA path handles any pending characters jumping them ahead of those characters that are pending under DMA. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/tty/serial/8250') diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 92dd18716169..388172289627 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1901,10 +1901,9 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) if (!up->dma->rx_running) break; fallthrough; + case UART_IIR_RLSI: case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); - fallthrough; - case UART_IIR_RLSI: return true; } return up->dma->rx_dma(up); -- cgit v1.2.3