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SubjectRe: [PATCH] mtd: fix timeout in M25P80 driver
Artem Bityutskiy wrote:
> On Mon, 2009-04-13 at 15:26 +0100, Peter Horton wrote:
>> 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.
>> - */
> Why did you remove the comment? Is it wrong or useless?
>

I moved the comment up to the definition of MAX_READY_WAIT_JIFFIES.
Looking through the code I missed the fact the driver can generate "chip
erase", on the M25P128 the maximum ready timeout for this is 250s !!!

P.


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