Messages in this thread | | | From | Martin Kepplinger <> | Subject | [PATCH v6 0/3] fix runtime PM for SD card readers | Date | Sun, 4 Jul 2021 09:54:00 +0200 |
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hi,
(According to Alan Stern, "as far as I know, all") SD card readers send MEDIA_CHANGED unit attention notification on (runtime) resume. We cannot use runtime PM with these devices as I/O always fails in that case.
This fixes runtime PM for SD cardreaders. I'd appreciate any feedback.
To enable runtime PM for an SD cardreader number 0:0:0:0, do:
echo 0 > /sys/module/block/parameters/events_dfl_poll_msecs echo 1000 > /sys/bus/scsi/devices/0:0:0:0/power/autosuspend_delay_ms echo auto > /sys/bus/scsi/devices/0:0:0:0/power/control
thank you, martin
revision history ---------------- v6: (thank you Bart and Christoph) * fix scsi command timeout for sense request * add reviewed-by tag
v5: (thank you Bart) * simplify the sense request itself and remove unnecessary code https://lore.kernel.org/linux-scsi/20210630084453.186764-1-martin.kepplinger@puri.sm/T/#t
v4: (thank you Bart and Alan) * send SENSE REQUEST in sd instead of adding a global scsi error flag. https://lore.kernel.org/linux-scsi/20210628133412.1172068-1-martin.kepplinger@puri.sm/T/#t
v3: (thank you Bart) * create a new BLIST entry to mark affected devices instead of the sysfs module parameter for sd only. still, only sd implements handling the flag for now. * cc linux-pm list https://lore.kernel.org/linux-scsi/20210328102531.1114535-1-martin.kepplinger@puri.sm/
v2: https://lore.kernel.org/linux-scsi/20210112093329.3639-1-martin.kepplinger@puri.sm/ * move module parameter to sd * add Documentation v1: https://lore.kernel.org/linux-scsi/20210111152029.28426-1-martin.kepplinger@puri.sm/T/
For the full background, the discussion started in June 2020 here: https://lore.kernel.org/linux-scsi/20200623111018.31954-1-martin.kepplinger@puri.sm/
Martin Kepplinger (3): scsi: devinfo: add new flag BLIST_MEDIA_CHANGE scsi: sd: send REQUEST SENSE for BLIST_MEDIA_CHANGE devices in runtime_resume() scsi: devinfo: add BLIST_MEDIA_CHANGE for Ultra HS-SD/MMC usb cardreaders
drivers/scsi/scsi_devinfo.c | 1 + drivers/scsi/sd.c | 23 ++++++++++++++++++++++- include/scsi/scsi_devinfo.h | 6 +++--- 3 files changed, 26 insertions(+), 4 deletions(-)
-- 2.30.2
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