aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mmc/core
diff options
context:
space:
mode:
authorRafael J. Wysocki <rjw@sisk.pl>2012-04-01 00:34:58 -0400
committerChris Ball <cjb@laptop.org>2012-04-05 20:32:26 -0400
commite841a7c69b708eeaf784fd517978006e8319b03a (patch)
treec8493c10b1cdd91c109cf2d95e7275d5f88f2a6c /drivers/mmc/core
parent6500c8ed957ac7b1ff37045ba6a2ad39ab2a8dbc (diff)
mmc: sdio: Use empty system suspend/resume callbacks at the bus level
Neil Brown reports that commit 35cd133c PM: Run the driver callback directly if the subsystem one is not there breaks suspend for his libertas wifi, because SDIO has a protocol where the suspend method can return -ENOSYS and this means "There is no point in suspending, just turn me off". Moreover, the suspend methods provided by SDIO drivers are not supposed to be called by the PM core or bus-level suspend routines (which aren't presend for SDIO). Instead, when the SDIO core gets to suspend the device's ancestor, it calls the device driver's suspend function, catches the ENOSYS, and turns the device off. The commit above breaks the SDIO core's assumption that the device drivers' callbacks won't be executed if it doesn't provide any bus-level callbacks. If fact, however, this assumption has never been really satisfied, because device class or device type suspend might very well use the driver's callback even without that commit. The simplest way to address this problem is to make the SDIO core tell the PM core to ignore driver callbacks, for example by providing no-operation suspend/resume callbacks at the bus level for it, which is implemented by this change. Reported-and-tested-by: Neil Brown <neilb@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> [stable: please apply to 3.3-stable only] Cc: <stable@vger.kernel.org> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r--drivers/mmc/core/sdio_bus.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/mmc/core/sdio_bus.c b/drivers/mmc/core/sdio_bus.c
index 40989e6bb53a..236842ec955a 100644
--- a/drivers/mmc/core/sdio_bus.c
+++ b/drivers/mmc/core/sdio_bus.c
@@ -192,9 +192,15 @@ static int sdio_bus_remove(struct device *dev)
192 return ret; 192 return ret;
193} 193}
194 194
195#ifdef CONFIG_PM_RUNTIME 195#ifdef CONFIG_PM
196
197static int pm_no_operation(struct device *dev)
198{
199 return 0;
200}
196 201
197static const struct dev_pm_ops sdio_bus_pm_ops = { 202static const struct dev_pm_ops sdio_bus_pm_ops = {
203 SET_SYSTEM_SLEEP_PM_OPS(pm_no_operation, pm_no_operation)
198 SET_RUNTIME_PM_OPS( 204 SET_RUNTIME_PM_OPS(
199 pm_generic_runtime_suspend, 205 pm_generic_runtime_suspend,
200 pm_generic_runtime_resume, 206 pm_generic_runtime_resume,
@@ -204,11 +210,11 @@ static const struct dev_pm_ops sdio_bus_pm_ops = {
204 210
205#define SDIO_PM_OPS_PTR (&sdio_bus_pm_ops) 211#define SDIO_PM_OPS_PTR (&sdio_bus_pm_ops)
206 212
207#else /* !CONFIG_PM_RUNTIME */ 213#else /* !CONFIG_PM */
208 214
209#define SDIO_PM_OPS_PTR NULL 215#define SDIO_PM_OPS_PTR NULL
210 216
211#endif /* !CONFIG_PM_RUNTIME */ 217#endif /* !CONFIG_PM */
212 218
213static struct bus_type sdio_bus_type = { 219static struct bus_type sdio_bus_type = {
214 .name = "sdio", 220 .name = "sdio",