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Fix erase timeout in M25P80 driver

PATCH In review Peter Horton 3 participants 3 messages Apr 4, 2009 Memory technology devices (MTD)

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Peter Horton

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#0 lore raw

PATCH 1/1 Fix erase 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 <[email protected]>

---

drivers/mtd/devices/m25p80.c +4 -7
Index: linux-2.6.29-git12/drivers/mtd/devices/m25p80.c
===================================================================
@@ -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

@@ -145,19 +145,16 @@
  */
 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++) {
+	for (deadline = jiffies + MAX_READY_WAIT_JIFFIES; !time_after_eq(jiffies, deadline);) {
 		if ((sr = read_sr(flash)) < 0)
 			break;
 		else if (!(sr & SR_WIP))
 			return 0;
 
-		/* REVISIT sometimes sleeping would be best */
+		cond_resched();
 	}
 
 	return 1;
Tested-by on v1 1/1
#1 lore raw
Quoted 7 lines · Peter Horton

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 <[email protected]>
Tested-by Martin Michlmayr <[email protected]>

This solves the problem I've seen on the QNAP TS-219.

Signature · 2 lines
Martin Michlmayr
http://www.cyrius.com/
#2 lore raw
In reply to Peter Horton
Quoted 1 line · Peter Horton

+       for (deadline = jiffies + MAX_READY_WAIT_JIFFIES; !time_after_eq(jiffies, deadline);) {

this would make more sense as a while loop:
deadline = jiffies + MAX_READY_WAIT_JIFFIES; while (!time_after_eq(jiffies, deadline)) {
maybe even more sense as a do { ... } while (...) ...

a for loop just looks weird ... but it should do what you want, so whatever -mike