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authorMasahiro Yamada <yamada.masahiro@socionext.com>2017-06-13 22:45:41 +0900
committerBoris Brezillon <boris.brezillon@free-electrons.com>2017-06-20 09:14:37 +0200
commitd49f5790278d18fd6b8e474397d9abfdf29a48f2 (patch)
treea128e070ed70fc11e3ddaa1c752523be78a5b526 /drivers/mtd/nand
parentf486287d2372422d68768c88fe54e80a48aee8ec (diff)
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/nand')
-rw-r--r--drivers/mtd/nand/denali.c28
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 */