[071/103] mmc: sdio: fix SDIO suspend/resume regression

From: Greg KH
Date: Fri Oct 22 2010 - 15:06:31 EST


2.6.35-stable review patch. If anyone has any objections, please let us know.

------------------

From: Ohad Ben-Cohen <ohad@xxxxxxxxxx>

commit 1c8cf9c997a4a6b36e907c7ede5f048aeaab1644 upstream.

Fix SDIO suspend/resume regression introduced by 4c2ef25fe0b "mmc: fix
all hangs related to mmc/sd card insert/removal during suspend/resume":

PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.01 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
Suspending console(s) (use no_console_suspend to debug)
pm_op(): platform_pm_suspend+0x0/0x5c returns -38
PM: Device pxa2xx-mci.0 failed to suspend: error -38
PM: Some devices failed to suspend

4c2ef25fe0b moved the card removal/insertion mechanism out of MMC's
suspend/resume path and into pm notifiers (mmc_pm_notify), and that
broke SDIO's expectation that mmc_suspend_host() will remove the card,
and squash the error, in case -ENOSYS is returned from the bus suspend
handler (mmc_sdio_suspend() in this case).

mmc_sdio_suspend() is using this whenever at least one of the card's SDIO
function drivers does not have suspend/resume handlers - in that case
it is agreed to force removal of the entire card.

This patch fixes this regression by trivially bringing back that part of
mmc_suspend_host(), which was removed by 4c2ef25fe0b.

Reported-and-tested-by: Sven Neumann <s.neumann@xxxxxxxxxxxx>
Signed-off-by: Ohad Ben-Cohen <ohad@xxxxxxxxxx>
Cc: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Acked-by: Nicolas Pitre <nico@xxxxxxxxxxx>
Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/mmc/core/core.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1277,6 +1277,19 @@ int mmc_suspend_host(struct mmc_host *ho
if (host->bus_ops && !host->bus_dead) {
if (host->bus_ops->suspend)
err = host->bus_ops->suspend(host);
+ if (err == -ENOSYS || !host->bus_ops->resume) {
+ /*
+ * We simply "remove" the card in this case.
+ * It will be redetected on resume.
+ */
+ if (host->bus_ops->remove)
+ host->bus_ops->remove(host);
+ mmc_claim_host(host);
+ mmc_detach_bus(host);
+ mmc_release_host(host);
+ host->pm_flags = 0;
+ err = 0;
+ }
}
mmc_bus_put(host);



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