| Message ID | 20090404073155.GA12392@turtle.localnet |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Apr 4, 2009 at 03:31, Peter Horton wrote: > static int wait_till_ready(struct m25p *flash) > { > - int count; > +# define DIV_U(n,d) (((n)+(d)-1)/(d)) > + > + unsigned long deadline; > int sr; > > - /* one chip guarantees max 5 msec wait here after page writes, > - * but potentially three seconds (!) after page erase. > + deadline = jiffies + DIV_U(MAX_READY_WAIT_TIMEOUT * HZ, 1000); there's already a macro for working with jiffies and time. dont start writing yet another one with its own ugly magic. just look in linux/jiffies.h. > + /* this can take a long time for sector erase. > + * we should probably have a separate timeout > + * for program and erase and we should check > + * for signals ... timeouts only occur when there's a problem. a problematic system is not normal, so having longer (and common) timeouts is fine because they should never be reached. -mike
--- linux-2.6.29-git8.orig/drivers/mtd/devices/m25p80.c 2009-03-23 23:12:14.000000000 +0000 +++ linux-2.6.29-git8/drivers/mtd/devices/m25p80.c 2009-04-02 20:37:47.000000000 +0100 @@ -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_TIMEOUT 7000 /* ms - M25P128 max is 6s */ #define CMD_SIZE 4 #ifdef CONFIG_M25PXX_USE_FAST_READ @@ -145,19 +145,25 @@ */ static int wait_till_ready(struct m25p *flash) { - int count; +# define DIV_U(n,d) (((n)+(d)-1)/(d)) + + unsigned long deadline; int sr; - /* one chip guarantees max 5 msec wait here after page writes, - * but potentially three seconds (!) after page erase. + deadline = jiffies + DIV_U(MAX_READY_WAIT_TIMEOUT * HZ, 1000); + + /* this can take a long time for sector erase. + * we should probably have a separate timeout + * for program and erase and we should check + * for signals ... */ - for (count = 0; count < MAX_READY_WAIT_COUNT; count++) { + while (!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;