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authorLinus Torvalds <torvalds@linux-foundation.org>2018-12-29 05:33:54 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-29 05:33:54 +0100
commit117eda8f71ff545cfdec8fe8073adbd173a1ceff (patch)
tree7a6fe1729d34581c563b5f7a883f049ee272f1e3 /drivers/tty/serial/8250
parentMerge tag 'usb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gre... (diff)
parentRevert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250" (diff)
downloadlinux-117eda8f71ff545cfdec8fe8073adbd173a1ceff.tar.xz
linux-117eda8f71ff545cfdec8fe8073adbd173a1ceff.zip
Merge tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH: "Here is the large TTY/Serial driver set of patches for 4.21-rc1. A number of small serial driver changes along with some good tty core fixes for long-reported issues with locking. There is also a new console font added to the tree, for high-res screens, so that should be helpful for many. The last patch in the series is a revert of an older one in the tree, it came late but it resolves a reported issue that linux-next was having for some people. Full details are in the shortlog, and all of these, with the exception of the revert, have been in linux-next for a while with no reported issues" * tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits) Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250" serial: sccnxp: Allow to use non-standard baud rates serial: sccnxp: Adds a delay between sequential read/write cycles tty: serial: qcom_geni_serial: Fix UART hang tty: serial: qcom_geni_serial: Fix wrap around of TX buffer serial: max310x: Fix tx_empty() callback dt-bindings: serial: sh-sci: Document r8a774c0 bindings dt-bindings: serial: sh-sci: Document r8a774a1 bindings Fonts: New Terminus large console font dt-bindings: serial: lpuart: add imx8qxp compatible string serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly serial: uartps: Fix error path when alloc failed serial: uartps: Check if the device is a console serial: uartps: Add the device_init_wakeup tty: serial: samsung: Increase maximum baudrate tty: serial: samsung: Properly set flags in autoCTS mode tty: Use of_node_name_{eq,prefix} for node name comparisons tty/serial: do not free trasnmit buffer page under port lock serial: 8250: Rate limit serial port rx interrupts during input overruns dt-bindings: serial: 8250: Add rate limit for serial port input overruns ...
Diffstat (limited to 'drivers/tty/serial/8250')
-rw-r--r--drivers/tty/serial/8250/8250_aspeed_vuart.c6
-rw-r--r--drivers/tty/serial/8250/8250_core.c25
-rw-r--r--drivers/tty/serial/8250/8250_fsl.c29
-rw-r--r--drivers/tty/serial/8250/8250_mtk.c210
-rw-r--r--drivers/tty/serial/8250/8250_of.c5
-rw-r--r--drivers/tty/serial/8250/8250_omap.c6
-rw-r--r--drivers/tty/serial/8250/8250_port.c8
7 files changed, 279 insertions, 10 deletions
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 435bec40dee6..0438d9a905ce 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -5,6 +5,10 @@
* Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp.
* Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
*/
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of_address.h>
@@ -293,7 +297,7 @@ static int aspeed_vuart_handle_irq(struct uart_port *port)
if (lsr & UART_LSR_THRE)
serial8250_tx_chars(up);
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_unlock_and_check_sysrq(port, flags);
return 1;
}
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 94f3e1c64490..189ab1212d9a 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -942,6 +942,21 @@ static struct uart_8250_port *serial8250_find_match_or_unused(struct uart_port *
return NULL;
}
+static void serial_8250_overrun_backoff_work(struct work_struct *work)
+{
+ struct uart_8250_port *up =
+ container_of(to_delayed_work(work), struct uart_8250_port,
+ overrun_backoff);
+ struct uart_port *port = &up->port;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ up->ier |= UART_IER_RLSI | UART_IER_RDI;
+ up->port.read_status_mask |= UART_LSR_DR;
+ serial_out(up, UART_IER, up->ier);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
/**
* serial8250_register_8250_port - register a serial port
* @up: serial port template
@@ -1056,6 +1071,16 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
ret = 0;
}
}
+
+ /* Initialise interrupt backoff work if required */
+ if (up->overrun_backoff_time_ms > 0) {
+ uart->overrun_backoff_time_ms = up->overrun_backoff_time_ms;
+ INIT_DELAYED_WORK(&uart->overrun_backoff,
+ serial_8250_overrun_backoff_work);
+ } else {
+ uart->overrun_backoff_time_ms = 0;
+ }
+
mutex_unlock(&serial_mutex);
return ret;
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index 6640a4c7ddd1..aa0e216d5ead 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -1,4 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
#include <linux/serial_reg.h>
#include <linux/serial_8250.h>
@@ -45,8 +49,29 @@ int fsl8250_handle_irq(struct uart_port *port)
lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);
- if (lsr & (UART_LSR_DR | UART_LSR_BI))
+ /* Process incoming characters first */
+ if ((lsr & (UART_LSR_DR | UART_LSR_BI)) &&
+ (up->ier & (UART_IER_RLSI | UART_IER_RDI))) {
lsr = serial8250_rx_chars(up, lsr);
+ }
+
+ /* Stop processing interrupts on input overrun */
+ if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {
+ unsigned long delay;
+
+ up->ier = port->serial_in(port, UART_IER);
+ if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
+ port->ops->stop_rx(port);
+ } else {
+ /* Keep restarting the timer until
+ * the input overrun subsides.
+ */
+ cancel_delayed_work(&up->overrun_backoff);
+ }
+
+ delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
+ schedule_delayed_work(&up->overrun_backoff, delay);
+ }
serial8250_modem_status(up);
@@ -54,7 +79,7 @@ int fsl8250_handle_irq(struct uart_port *port)
serial8250_tx_chars(up);
up->lsr_saved_flags = orig_lsr;
- spin_unlock_irqrestore(&up->port.lock, flags);
+ uart_unlock_and_check_sysrq(&up->port, flags);
return 1;
}
EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index c3f933d10295..e2c407656fa6 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -14,6 +14,10 @@
#include <linux/pm_runtime.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
+#include <linux/console.h>
+#include <linux/dma-mapping.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
#include "8250.h"
@@ -22,12 +26,172 @@
#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
+#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
+#define MTK_UART_DMA_EN_TX 0x2
+#define MTK_UART_DMA_EN_RX 0x5
+
+#define MTK_UART_TX_SIZE UART_XMIT_SIZE
+#define MTK_UART_RX_SIZE 0x8000
+#define MTK_UART_TX_TRIGGER 1
+#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE
+
+#ifdef CONFIG_SERIAL_8250_DMA
+enum dma_rx_status {
+ DMA_RX_START = 0,
+ DMA_RX_RUNNING = 1,
+ DMA_RX_SHUTDOWN = 2,
+};
+#endif
+
struct mtk8250_data {
int line;
+ unsigned int rx_pos;
struct clk *uart_clk;
struct clk *bus_clk;
+ struct uart_8250_dma *dma;
+#ifdef CONFIG_SERIAL_8250_DMA
+ enum dma_rx_status rx_status;
+#endif
};
+#ifdef CONFIG_SERIAL_8250_DMA
+static void mtk8250_rx_dma(struct uart_8250_port *up);
+
+static void mtk8250_dma_rx_complete(void *param)
+{
+ struct uart_8250_port *up = param;
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ struct tty_port *tty_port = &up->port.state->port;
+ struct dma_tx_state state;
+ unsigned char *ptr;
+ int copied;
+
+ dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
+ dma->rx_size, DMA_FROM_DEVICE);
+
+ dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+
+ if (data->rx_status == DMA_RX_SHUTDOWN)
+ return;
+
+ if ((data->rx_pos + state.residue) <= dma->rx_size) {
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr, state.residue);
+ } else {
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr,
+ dma->rx_size - data->rx_pos);
+ ptr = (unsigned char *)(dma->rx_buf);
+ copied += tty_insert_flip_string(tty_port, ptr,
+ data->rx_pos + state.residue - dma->rx_size);
+ }
+ up->port.icount.rx += copied;
+
+ tty_flip_buffer_push(tty_port);
+
+ mtk8250_rx_dma(up);
+}
+
+static void mtk8250_rx_dma(struct uart_8250_port *up)
+{
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ struct dma_async_tx_descriptor *desc;
+ struct dma_tx_state state;
+
+ desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
+ dma->rx_size, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ pr_err("failed to prepare rx slave single\n");
+ return;
+ }
+
+ desc->callback = mtk8250_dma_rx_complete;
+ desc->callback_param = up;
+
+ dma->rx_cookie = dmaengine_submit(desc);
+
+ dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ data->rx_pos = state.residue;
+
+ dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
+ dma->rx_size, DMA_FROM_DEVICE);
+
+ dma_async_issue_pending(dma->rxchan);
+}
+
+static void mtk8250_dma_enable(struct uart_8250_port *up)
+{
+ struct uart_8250_dma *dma = up->dma;
+ struct mtk8250_data *data = up->port.private_data;
+ int lcr = serial_in(up, UART_LCR);
+
+ if (data->rx_status != DMA_RX_START)
+ return;
+
+ dma->rxconf.direction = DMA_DEV_TO_MEM;
+ dma->rxconf.src_addr_width = dma->rx_size / 1024;
+ dma->rxconf.src_addr = dma->rx_addr;
+
+ dma->txconf.direction = DMA_MEM_TO_DEV;
+ dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024;
+ dma->txconf.dst_addr = dma->tx_addr;
+
+ serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
+ UART_FCR_CLEAR_XMIT);
+ serial_out(up, MTK_UART_DMA_EN,
+ MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
+
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ serial_out(up, UART_EFR, UART_EFR_ECB);
+ serial_out(up, UART_LCR, lcr);
+
+ if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
+ pr_err("failed to configure rx dma channel\n");
+ if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
+ pr_err("failed to configure tx dma channel\n");
+
+ data->rx_status = DMA_RX_RUNNING;
+ data->rx_pos = 0;
+ mtk8250_rx_dma(up);
+}
+#endif
+
+static int mtk8250_startup(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+ struct uart_8250_port *up = up_to_u8250p(port);
+ struct mtk8250_data *data = port->private_data;
+
+ /* disable DMA for console */
+ if (uart_console(port))
+ up->dma = NULL;
+
+ if (up->dma) {
+ data->rx_status = DMA_RX_START;
+ uart_circ_clear(&port->state->xmit);
+ }
+#endif
+ memset(&port->icount, 0, sizeof(port->icount));
+
+ return serial8250_do_startup(port);
+}
+
+static void mtk8250_shutdown(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_8250_DMA
+ struct uart_8250_port *up = up_to_u8250p(port);
+ struct mtk8250_data *data = port->private_data;
+
+ if (up->dma)
+ data->rx_status = DMA_RX_SHUTDOWN;
+#endif
+
+ return serial8250_do_shutdown(port);
+}
+
static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
@@ -36,6 +200,17 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
unsigned long flags;
unsigned int baud, quot;
+#ifdef CONFIG_SERIAL_8250_DMA
+ if (up->dma) {
+ if (uart_console(port)) {
+ devm_kfree(up->port.dev, up->dma);
+ up->dma = NULL;
+ } else {
+ mtk8250_dma_enable(up);
+ }
+ }
+#endif
+
serial8250_do_set_termios(port, termios, old);
/*
@@ -143,9 +318,20 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
pm_runtime_put_sync_suspend(port->dev);
}
+#ifdef CONFIG_SERIAL_8250_DMA
+static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
+{
+ return false;
+}
+#endif
+
static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
struct mtk8250_data *data)
{
+#ifdef CONFIG_SERIAL_8250_DMA
+ int dmacnt;
+#endif
+
data->uart_clk = devm_clk_get(&pdev->dev, "baud");
if (IS_ERR(data->uart_clk)) {
/*
@@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
}
data->bus_clk = devm_clk_get(&pdev->dev, "bus");
- return PTR_ERR_OR_ZERO(data->bus_clk);
+ if (IS_ERR(data->bus_clk))
+ return PTR_ERR(data->bus_clk);
+
+ data->dma = NULL;
+#ifdef CONFIG_SERIAL_8250_DMA
+ dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
+ if (dmacnt == 2) {
+ data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
+ GFP_KERNEL);
+ data->dma->fn = mtk8250_dma_filter;
+ data->dma->rx_size = MTK_UART_RX_SIZE;
+ data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
+ data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
+ }
+#endif
+
+ return 0;
}
static int mtk8250_probe(struct platform_device *pdev)
@@ -204,8 +406,14 @@ static int mtk8250_probe(struct platform_device *pdev)
uart.port.iotype = UPIO_MEM32;
uart.port.regshift = 2;
uart.port.private_data = data;
+ uart.port.shutdown = mtk8250_shutdown;
+ uart.port.startup = mtk8250_startup;
uart.port.set_termios = mtk8250_set_termios;
uart.port.uartclk = clk_get_rate(data->uart_clk);
+#ifdef CONFIG_SERIAL_8250_DMA
+ if (data->dma)
+ uart.dma = data->dma;
+#endif
/* Disable Rate Fix function */
writel(0x0, uart.port.membase +
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 877fd7f8a8ed..a1a85805d010 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -240,6 +240,11 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
if (of_property_read_bool(ofdev->dev.of_node, "auto-flow-control"))
port8250.capabilities |= UART_CAP_AFE;
+ if (of_property_read_u32(ofdev->dev.of_node,
+ "overrun-throttle-ms",
+ &port8250.overrun_backoff_time_ms) != 0)
+ port8250.overrun_backoff_time_ms = 0;
+
ret = serial8250_register_8250_port(&port8250);
if (ret < 0)
goto err_dispose;
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index a019286f8bb6..ad7ba7d0f28d 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -8,6 +8,10 @@
*
*/
+#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -1085,7 +1089,7 @@ static int omap_8250_dma_handle_irq(struct uart_port *port)
}
}
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_unlock_and_check_sysrq(port, flags);
serial8250_rpm_put(up);
return 1;
}
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 3f779d25ec0c..d2f3310abe54 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1736,7 +1736,7 @@ void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
else if (lsr & UART_LSR_FE)
flag = TTY_FRAME;
}
- if (uart_handle_sysrq_char(port, ch))
+ if (uart_prepare_sysrq_char(port, ch))
return;
uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
@@ -1878,7 +1878,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE))
serial8250_tx_chars(up);
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_unlock_and_check_sysrq(port, flags);
return 1;
}
EXPORT_SYMBOL_GPL(serial8250_handle_irq);
@@ -3239,9 +3239,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s,
serial8250_rpm_get(up);
- if (port->sysrq)
- locked = 0;
- else if (oops_in_progress)
+ if (oops_in_progress)
locked = spin_trylock_irqsave(&port->lock, flags);
else
spin_lock_irqsave(&port->lock, flags);