The patch titled
mmc: omap: do not busy wait for end of command for ever
has been added to the -mm tree. Its filename is
mmc-omap-do-not-busy-wait-for-end-of-command-for-ever.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mmc: omap: do not busy wait for end of command for ever
From: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx>
The limit was a fixed 100k limit in the busy loop, which is not accurate. It
would better to have time limit for the worst case which occurs when sending
80 cycles at 400 kHz and takes about 200 microseconds, so limit the max time
spend in the busy loop for some 250 microseconds.
Signed-off-by: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Pierre Ossman <drzeus-list@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/omap.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff -puN drivers/mmc/host/omap.c~mmc-omap-do-not-busy-wait-for-end-of-command-for-ever drivers/mmc/host/omap.c
--- a/drivers/mmc/host/omap.c~mmc-omap-do-not-busy-wait-for-end-of-command-for-ever
+++ a/drivers/mmc/host/omap.c
@@ -1276,11 +1276,17 @@ static void mmc_omap_set_ios(struct mmc_
OMAP_MMC_WRITE(host, CON, dsor);
slot->saved_con = dsor;
if (ios->power_mode == MMC_POWER_ON) {
+ /* worst case at 400kHz, 80 cycles makes 200 microsecs */
+ int usecs = 250;
+
/* Send clock cycles, poll completion */
OMAP_MMC_WRITE(host, IE, 0);
OMAP_MMC_WRITE(host, STAT, 0xffff);
OMAP_MMC_WRITE(host, CMD, 1 << 7);
- while ((OMAP_MMC_READ(host, STAT) & 1) == 0);
+ while (usecs > 0 && (OMAP_MMC_READ(host, STAT) & 1) == 0) {
+ udelay(1);
+ usecs--;
+ }
OMAP_MMC_WRITE(host, STAT, 1);
}
_
Patches currently in -mm which might be from jarkko.lavinen@xxxxxxxxx are
mmc-omap-introduce-new-multislot-structure-and-change-driver-to-use-it.patch
mmc-omap-add-back-cover-switch-support.patch
mmc-omap-fix-timeout-calculation-for-mmc-multislot-support.patch
mmc-omap-abort-stuck-commands.patch
mmc-omap-use-tasklet-instead-of-workqueue-for-cover-switch-notification.patch
mmc-omap-move-failing-command-abortion-to-workqueue.patch
mmc-omap-lazy-clock-shutdown.patch
mmc-omap-start-new-commands-from-work-queue-instead-of-irq.patch
mmc-omap-do-not-busy-wait-for-end-of-command-for-ever.patch
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