lkml.org 
[lkml]   [2012]   [Mar]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    SubjectRe: Recent "Run the driver callback directly" patch breaks libertas suspend
    Date
    On Sunday, March 25, 2012, Rafael J. Wysocki wrote:
    > Hi,
    >
    > On Sunday, March 25, 2012, NeilBrown wrote:
    > >
    > > Hi Rafael,
    > >
    > > Your recent patch:
    > > commit 35cd133c
    > > PM: Run the driver callback directly if the subsystem one is not there
    > >
    > > breaks suspend for my libertas wifi and probably other SDIO devices.
    >
    > Well, the patch is not recent. The _commit_ is more than three months old
    > and the patch has been around since the last November (at least).
    >
    > > SDIO (and possible MMC in general) has a protocol where the suspend
    > > method can return -ENOSYS and this means "There is no point in suspending,
    > > just turn me off".
    > >
    > > The device itself "mmc1:0001" (I think) doesn't have any bus etc 'suspend'
    > > function so the new code call the device's suspend function which returns
    > > ENOSYS and the suspend fails.
    > >
    > > The previous code ignores the device as there is no bus suspend, and when it
    > > gets to suspend the ancestor - which for me is omap_hsmmc.1, it calls the
    > > device suspend function catches the ENOSYS, and turns it off.
    >
    > Well, I can only call that a blatant abuse of the PM infrastructure.
    >
    > > I suspect just reverting it isn't the right long term solution, however I
    > > can confirm that it works for me for now.
    >
    > It's not a solution at all, because there's code that depends on it already in
    > the tree and the fact that it works for you doesn't mean it won't break other
    > systems. So no, it's not an option.
    >
    > > I'm happy to try any alternate fixes you would like to suggest (but I cannot
    > > promise how quickly I will get the testing done).
    > >
    > > (I'm testing with 3.3)
    >
    > The only fix I can think of is to rework SDIO to stop abusing the PM callbacks.
    > I'll have a look at that next week, although I can't promise anything any time
    > soon, because I'm heading to San Francisco on Saturday.

    Well, this is kind of a long shot, but I wonder if the patch below makes
    any difference?

    Rafael

    ---
    drivers/mmc/core/sdio_bus.c | 12 +++++++++---
    1 file changed, 9 insertions(+), 3 deletions(-)

    Index: linux/drivers/mmc/core/sdio_bus.c
    ===================================================================
    --- linux.orig/drivers/mmc/core/sdio_bus.c
    +++ linux/drivers/mmc/core/sdio_bus.c
    @@ -192,9 +192,15 @@ static int sdio_bus_remove(struct device
    return ret;
    }

    -#ifdef CONFIG_PM_RUNTIME
    +#ifdef CONFIG_PM
    +
    +static int pm_no_operation(struct device *dev)
    +{
    + return 0;
    +}

    static const struct dev_pm_ops sdio_bus_pm_ops = {
    + SET_SYSTEM_SLEEP_PM_OPS(pm_no_operation, pm_no_operation)
    SET_RUNTIME_PM_OPS(
    pm_generic_runtime_suspend,
    pm_generic_runtime_resume,
    @@ -204,11 +210,11 @@ static const struct dev_pm_ops sdio_bus_

    #define SDIO_PM_OPS_PTR (&sdio_bus_pm_ops)

    -#else /* !CONFIG_PM_RUNTIME */
    +#else /* !CONFIG_PM */

    #define SDIO_PM_OPS_PTR NULL

    -#endif /* !CONFIG_PM_RUNTIME */
    +#endif /* !CONFIG_PM */

    static struct bus_type sdio_bus_type = {
    .name = "sdio",

    \
     
     \ /
      Last update: 2012-03-25 23:25    [W:0.029 / U:0.176 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site