On 13 October 2016 at 13:37, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > The rtsx_usb_sdmmc (mmc/sd) and rtsx_usb_ms (memstick) devices are interfacing > an rtsx_usb device (managed by an mfd driver) while communicating with the > cards. The mmc/sd and memstick devices are children of the usb device. > > Issues has been reported [1] for rtsx, which have been investigated, discussed, > fixed, tested, etc, particularly when using mmc/sd cards. During the > investigation, some changes was proposed and tested successfully. In this > series I have picked up these changes and created some proper patches with > change-logs. > > It turned out that most of the problems was related to the runtime PM > deployment in the memstick and the mmc/sd driver, which are fixed in this > series. > > A couple of more issues were also discussed [2], which needs to be fixed as > well. Although they are out of scope for this series, so we will have to look > into those at a later point. Here's a brief summary of these leftovers: > > *) > It seems reasonable to turn off autosuspend for usb devices and instead rely on > the usb device's children to deal with autosuspend. The reason is simply that > the children has better knowledge of when using autosuspend makes sense. > > **) > Polling card detect mode is used both for mmc/sd and memstick. Because of the > lack of synchronization between the polling attempts for these subsystems, the > usb device may be powered on for unnecessary long intervals, thus we are > wasting power. > > Besides the above changes, I folded in a change in the mmc core which improves > the behaviour for mmc hosts using MMC_CAP2_NO_PRESCAN_POWERUP, which is the > case for the rtsx_usb_sdmmc driver. This change should improve the boot time > with ~100ms per rtsx_usb_sdmmc device. > > Finally, as I couldn't find an active maintainer for the memstick > subsystem/driver and because the author of the drivers can be reached, I > volunteer to take this all through my mmc tree. Please tell me if that is > problem to any of you. > > [1] > https://www.spinics.net/lists/linux-usb/msg146998.html > [2] > https://www.spinics.net/lists/linux-mmc/msg39235.html > > > Alan Stern (1): > memstick: rtsx_usb_ms: Runtime resume the device when polling for > cards > > Ulf Hansson (5): > mmc: rtsx_usb_sdmmc: Avoid keeping the device runtime resumed when > unused > mmc: rtsx_usb_sdmmc: Handle runtime PM while changing the led > memstick: rtsx_usb_ms: Manage runtime PM when accessing the device > mmc: rtsx_usb_sdmmc: Enable runtime PM autosuspend > mmc: core: Don't power off the card when starting the host > > drivers/memstick/host/rtsx_usb_ms.c | 6 ++++++ > drivers/mmc/core/core.c | 9 ++++----- > drivers/mmc/host/rtsx_usb_sdmmc.c | 10 +++++----- > 3 files changed, 15 insertions(+), 10 deletions(-) > > -- > 1.9.1 > Patch 1->4 applied for fixes. Holding patch 5->6 for a while, as they are intended for next! Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
