* [PATCH v2, Repost]: NAND: Add panic_write for NAND flashes
[not found] ` <20091002101431.GI9644@edde.se.axis.com>
@ 2009-10-05 13:55 ` Simon Kagstrom
2009-10-08 5:15 ` Artem Bityutskiy
0 siblings, 1 reply; 2+ messages in thread
From: Simon Kagstrom @ 2009-10-05 13:55 UTC (permalink / raw)
To: linux-mtd, Artem Bityutskiy; +Cc: Edgar E. Iglesias
This is a quick and dirty patch to add panic_write for NAND flashes. The
patch seems to work OK on my CRIS board running a 2.6.26 kernel with a
ID: 0x20, Chip ID: 0xf1 (ST Micro NAND 128MiB 3,3V 8-bit), and also on a
OpenRD base (Marvell Kirkwood) board with a Toshiba NAND 512MiB 3,3V
8-bit flash with 2.6.32-pre1.
Signed-off-by: Edgar E. Iglesias <edgar@axis.com>
Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
---
ChangeLog:
v2: Fix issues from Artem
* Fix comments about 400ms and question marks
* Add oops_in_progress to panic_nand_wait condition
* Change prototype for panic_nand_get_device
* Make some changes to the patch description
drivers/mtd/nand/nand_base.c | 128 +++++++++++++++++++++++++++++++++++++++---
1 files changed, 120 insertions(+), 8 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 2211386..c5fbfee 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -428,6 +428,28 @@ static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip,
return nand_isbad_bbt(mtd, ofs, allowbbt);
}
+/**
+ * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands.
+ * @mtd: MTD device structure
+ * @timeo: Timeout
+ *
+ * Helper function for nand_wait_ready used when needing to wait in interrupt
+ * context.
+ */
+static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo)
+{
+ struct nand_chip *chip = mtd->priv;
+ int i;
+
+ /* Wait for the device to get ready */
+ for (i = 0; i < timeo; i++) {
+ if (chip->dev_ready(mtd))
+ break;
+ touch_softlockup_watchdog();
+ mdelay(1);
+ }
+}
+
/*
* Wait for the ready pin, after a command
* The timeout is catched later.
@@ -437,6 +459,10 @@ void nand_wait_ready(struct mtd_info *mtd)
struct nand_chip *chip = mtd->priv;
unsigned long timeo = jiffies + 2;
+ /* 400ms timeout */
+ if (in_interrupt() || oops_in_progress)
+ return panic_nand_wait_ready(mtd, 400);
+
led_trigger_event(nand_led_trigger, LED_FULL);
/* wait until command is processed or timeout occures */
do {
@@ -672,6 +698,22 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command,
}
/**
+ * panic_nand_get_device - [GENERIC] Get chip for selected access
+ * @chip: the nand chip descriptor
+ * @mtd: MTD device structure
+ * @new_state: the state which is requested
+ *
+ * Used when in panic, no locks are taken.
+ */
+static void panic_nand_get_device(struct nand_chip *chip,
+ struct mtd_info *mtd, int new_state)
+{
+ /* Hardware controller shared among independend devices */
+ chip->controller->active = chip;
+ chip->state = new_state;
+}
+
+/**
* nand_get_device - [GENERIC] Get chip for selected access
* @chip: the nand chip descriptor
* @mtd: MTD device structure
@@ -710,6 +752,32 @@ nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state)
}
/**
+ * panic_nand_wait - [GENERIC] wait until the command is done
+ * @mtd: MTD device structure
+ * @chip: NAND chip structure
+ * @timeo: Timeout
+ *
+ * Wait for command done. This is a helper function for nand_wait used when
+ * we are in interrupt context. May happen when in panic and trying to write
+ * an oops trough mtdoops.
+ */
+static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip,
+ unsigned long timeo)
+{
+ int i;
+ for (i = 0; i < timeo; i++) {
+ if (chip->dev_ready) {
+ if (chip->dev_ready(mtd))
+ break;
+ } else {
+ if (chip->read_byte(mtd) & NAND_STATUS_READY)
+ break;
+ }
+ mdelay(1);
+ }
+}
+
+/**
* nand_wait - [DEFAULT] wait until the command is done
* @mtd: MTD device structure
* @chip: NAND chip structure
@@ -740,15 +808,19 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
else
chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1);
- while (time_before(jiffies, timeo)) {
- if (chip->dev_ready) {
- if (chip->dev_ready(mtd))
- break;
- } else {
- if (chip->read_byte(mtd) & NAND_STATUS_READY)
- break;
+ if (in_interrupt() || oops_in_progress)
+ panic_nand_wait(mtd, chip, timeo);
+ else {
+ while (time_before(jiffies, timeo)) {
+ if (chip->dev_ready) {
+ if (chip->dev_ready(mtd))
+ break;
+ } else {
+ if (chip->read_byte(mtd) & NAND_STATUS_READY)
+ break;
+ }
+ cond_resched();
}
- cond_resched();
}
led_trigger_event(nand_led_trigger, LED_OFF);
@@ -1943,6 +2015,45 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
}
/**
+ * panic_nand_write - [MTD Interface] NAND write with ECC
+ * @mtd: MTD device structure
+ * @to: offset to write to
+ * @len: number of bytes to write
+ * @retlen: pointer to variable to store the number of written bytes
+ * @buf: the data to write
+ *
+ * NAND write with ECC. Used when performing writes in interrupt context, this
+ * may for example be called by mtdoops when writing an oops while in panic.
+ */
+static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const uint8_t *buf)
+{
+ struct nand_chip *chip = mtd->priv;
+ int ret;
+
+ /* Do not allow reads past end of device */
+ if ((to + len) > mtd->size)
+ return -EINVAL;
+ if (!len)
+ return 0;
+
+ /* Wait for the device to get ready. */
+ panic_nand_wait(mtd, chip, 400);
+
+ /* Grab the device. */
+ panic_nand_get_device(chip, mtd, FL_WRITING);
+
+ chip->ops.len = len;
+ chip->ops.datbuf = (uint8_t *)buf;
+ chip->ops.oobbuf = NULL;
+
+ ret = nand_do_write_ops(mtd, to, &chip->ops);
+
+ *retlen = chip->ops.retlen;
+ return ret;
+}
+
+/**
* nand_write - [MTD Interface] NAND write with ECC
* @mtd: MTD device structure
* @to: offset to write to
@@ -2871,6 +2982,7 @@ int nand_scan_tail(struct mtd_info *mtd)
mtd->unpoint = NULL;
mtd->read = nand_read;
mtd->write = nand_write;
+ mtd->panic_write = panic_nand_write;
mtd->read_oob = nand_read_oob;
mtd->write_oob = nand_write_oob;
mtd->sync = nand_sync;
--
1.6.0.4
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