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Subject[PATCH] mtd: fix timeout in M25P80 driver
Extend erase timeout in M25P80 SPI Flash driver.

The M25P80 drivers fails erasing sectors on a M25P128 because the ready
wait timeout is too short. Change the timeout from a simple loop count to a
suitable number of seconds.

Signed-off-by: Peter Horton <zero@colonel-panic.org>
---
Index: linux-2.6.29-git12/drivers/mtd/devices/m25p80.c
===================================================================
--- linux-2.6.29-git12.orig/drivers/mtd/devices/m25p80.c 2009-04-12 21:41:16.000000000 +0000
+++ linux-2.6.29-git12/drivers/mtd/devices/m25p80.c 2009-04-12 21:43:01.000000000 +0000
@@ -54,7 +54,7 @@
#define SR_SRWD 0x80 /* SR write protect */

/* Define max times to check status register before we give up. */
-#define MAX_READY_WAIT_COUNT 100000
+#define MAX_READY_WAIT_JIFFIES (10 * HZ) /* eg. M25P128 specs 6s max sector erase */
#define CMD_SIZE 4

#ifdef CONFIG_M25PXX_USE_FAST_READ
@@ -145,20 +145,20 @@
*/
static int wait_till_ready(struct m25p *flash)
{
- int count;
+ unsigned long deadline;
int sr;

- /* one chip guarantees max 5 msec wait here after page writes,
- * but potentially three seconds (!) after page erase.
- */
- for (count = 0; count < MAX_READY_WAIT_COUNT; count++) {
+ deadline = jiffies + MAX_READY_WAIT_JIFFIES;
+
+ do {
if ((sr = read_sr(flash)) < 0)
break;
else if (!(sr & SR_WIP))
return 0;

- /* REVISIT sometimes sleeping would be best */
- }
+ cond_resched();
+
+ } while (!time_after_eq(jiffies, deadline));

return 1;
}

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