[PATCH] mtd: fix timeout in M25P80 driver
Artem Bityutskiy
dedekind at infradead.org
Fri Apr 17 05:21:28 EDT 2009
On Fri, 2009-04-17 at 09:22 +0100, Peter Horton wrote:
> 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 at 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 !!!
So I assume you are going to send another patch? Also, how about
Andrew's suggestion not to hog CPU?
--
Best regards,
Artem Bityutskiy (Битюцкий Артём)
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