diff options
| author | Masahiro Yamada <yamada.masahiro@socionext.com> | 2017-06-13 15:45:41 +0200 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@free-electrons.com> | 2017-06-20 09:14:37 +0200 |
| commit | d49f5790278d18fd6b8e474397d9abfdf29a48f2 (patch) | |
| tree | a128e070ed70fc11e3ddaa1c752523be78a5b526 /drivers/mtd | |
| parent | mtd: nand: denali: fix bank reset function to detect the number of chips (diff) | |
| download | linux-d49f5790278d18fd6b8e474397d9abfdf29a48f2.tar.xz linux-d49f5790278d18fd6b8e474397d9abfdf29a48f2.zip | |
mtd: nand: denali: use interrupt instead of polling for bank reset
The current bank reset implementation polls the INTR_STATUS register
until interested bits are set. This is not good because:
- polling simply wastes time-slice of the thread
- The while() loop may continue eternally if no bit is set, for
example, due to the controller problem. The denali_wait_for_irq()
uses wait_for_completion_timeout(), which is safer.
We can use interrupt by moving the denali_reset_bank() call below
the interrupt setup.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Diffstat (limited to 'drivers/mtd')
| -rw-r--r-- | drivers/mtd/nand/denali.c | 28 |
1 files changed, 14 insertions, 14 deletions
diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c index 3169ba58c58a..31d987d26e12 100644 --- a/drivers/mtd/nand/denali.c +++ b/drivers/mtd/nand/denali.c @@ -1028,24 +1028,25 @@ static int denali_setup_data_interface(struct mtd_info *mtd, int chipnr, static void denali_reset_banks(struct denali_nand_info *denali) { + u32 irq_status; int i; - denali_clear_irq_all(denali); - for (i = 0; i < denali->max_banks; i++) { - iowrite32(1 << i, denali->flash_reg + DEVICE_RESET); - while (!(ioread32(denali->flash_reg + INTR_STATUS(i)) & - (INTR__RST_COMP | INTR__TIME_OUT))) - cpu_relax(); - if (!(ioread32(denali->flash_reg + INTR_STATUS(i)) & - INTR__INT_ACT)) + denali->flash_bank = i; + + denali_reset_irq(denali); + + iowrite32(DEVICE_RESET__BANK(i), + denali->flash_reg + DEVICE_RESET); + + irq_status = denali_wait_for_irq(denali, + INTR__RST_COMP | INTR__INT_ACT | INTR__TIME_OUT); + if (!(irq_status & INTR__INT_ACT)) break; } dev_dbg(denali->dev, "%d chips connected\n", i); denali->max_banks = i; - - denali_clear_irq_all(denali); } static void denali_hw_init(struct denali_nand_info *denali) @@ -1067,7 +1068,6 @@ static void denali_hw_init(struct denali_nand_info *denali) denali->bbtskipbytes = ioread32(denali->flash_reg + SPARE_AREA_SKIP_BYTES); detect_max_banks(denali); - denali_reset_banks(denali); iowrite32(0x0F, denali->flash_reg + RB_PIN_ENABLED); iowrite32(CHIP_EN_DONT_CARE__FLAG, denali->flash_reg + CHIP_ENABLE_DONT_CARE); @@ -1185,9 +1185,6 @@ static void denali_drv_init(struct denali_nand_info *denali) * element that might be access shared data (interrupt status) */ spin_lock_init(&denali->irq_lock); - - /* indicate that MTD has not selected a valid bank yet */ - denali->flash_bank = CHIP_SELECT_INVALID; } static int denali_multidev_fixup(struct denali_nand_info *denali) @@ -1262,6 +1259,9 @@ int denali_init(struct denali_nand_info *denali) } denali_enable_irq(denali); + denali_reset_banks(denali); + + denali->flash_bank = CHIP_SELECT_INVALID; nand_set_flash_node(chip, denali->dev->of_node); /* Fallback to the default name if DT did not give "label" property */ |