| Message ID | 20210630084453.186764-3-martin.kepplinger@puri.sm (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | fix runtime PM for SD card readers | expand |
On 6/30/21 1:44 AM, Martin Kepplinger wrote: > For SD cardreader devices that have the BLIST_MEDIA_CHANGE flag set, > a MEDIA CHANGE unit attention is received after resuming from runtime > suspend. Send a REQUEST SENSE to avoid that. Reviewed-by: Bart Van Assche <bvanassche@acm.org>
On Wed, Jun 30, 2021 at 10:44:52AM +0200, Martin Kepplinger wrote: > + struct scsi_disk *sdkp = dev_get_drvdata(dev); > + struct scsi_device *sdp = sdkp->device; > + int timeout, res; > + > + timeout = sdp->request_queue->rq_timeout * SD_FLUSH_TIMEOUT_MULTIPLIER; Is REQUEST SENSE reqlly a so slow operation on these devices that we need to override the timeout?
Am Donnerstag, dem 01.07.2021 um 15:49 +0100 schrieb Christoph Hellwig: > On Wed, Jun 30, 2021 at 10:44:52AM +0200, Martin Kepplinger wrote: > > + struct scsi_disk *sdkp = dev_get_drvdata(dev); > > + struct scsi_device *sdp = sdkp->device; > > + int timeout, res; > > + > > + timeout = sdp->request_queue->rq_timeout * > > SD_FLUSH_TIMEOUT_MULTIPLIER; > > Is REQUEST SENSE reqlly a so slow operation on these devices that > we need to override the timeout? using SD_TIMEOUT works equally fine for me. Is that what you'd rather like to see? Bart, is SD_TIMEOUT equally ok for you? If so, I'll resend with your reviewed-by. thank you for reviewing! martin
On 7/2/21 1:04 AM, Martin Kepplinger wrote: > Am Donnerstag, dem 01.07.2021 um 15:49 +0100 schrieb Christoph Hellwig: >> On Wed, Jun 30, 2021 at 10:44:52AM +0200, Martin Kepplinger wrote: >>> + struct scsi_disk *sdkp = dev_get_drvdata(dev); >>> + struct scsi_device *sdp = sdkp->device; >>> + int timeout, res; >>> + >>> + timeout = sdp->request_queue->rq_timeout * >>> SD_FLUSH_TIMEOUT_MULTIPLIER; >> >> Is REQUEST SENSE reqlly a so slow operation on these devices that >> we need to override the timeout? > > using SD_TIMEOUT works equally fine for me. Is that what you'd rather > like to see? > > Bart, is SD_TIMEOUT equally ok for you? If so, I'll resend with your > reviewed-by. Hi Martin, I prefer sdp->request_queue->rq_timeout instead of SD_TIMEOUT since the former is configurable via sysfs. Thanks, Bart.
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 6d2d63629a90..b02378f40620 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -63,6 +63,7 @@ #include <scsi/scsi_cmnd.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_device.h> +#include <scsi/scsi_devinfo.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_host.h> @@ -114,6 +115,7 @@ static void sd_shutdown(struct device *); static int sd_suspend_system(struct device *); static int sd_suspend_runtime(struct device *); static int sd_resume(struct device *); +static int sd_resume_runtime(struct device *); static void sd_rescan(struct device *); static blk_status_t sd_init_command(struct scsi_cmnd *SCpnt); static void sd_uninit_command(struct scsi_cmnd *SCpnt); @@ -608,7 +610,7 @@ static const struct dev_pm_ops sd_pm_ops = { .poweroff = sd_suspend_system, .restore = sd_resume, .runtime_suspend = sd_suspend_runtime, - .runtime_resume = sd_resume, + .runtime_resume = sd_resume_runtime, }; static struct scsi_driver sd_template = { @@ -3720,6 +3722,28 @@ static int sd_resume(struct device *dev) return ret; } +static int sd_resume_runtime(struct device *dev) +{ + struct scsi_disk *sdkp = dev_get_drvdata(dev); + struct scsi_device *sdp = sdkp->device; + int timeout, res; + + timeout = sdp->request_queue->rq_timeout * SD_FLUSH_TIMEOUT_MULTIPLIER; + + if (sdp->sdev_bflags & BLIST_MEDIA_CHANGE) { + /* clear the devices' sense data */ + static const u8 cmd[10] = { REQUEST_SENSE }; + + res = scsi_execute(sdp, cmd, DMA_NONE, NULL, 0, NULL, + NULL, timeout, 1, 0, RQF_PM, NULL); + if (res) + sd_printk(KERN_NOTICE, sdkp, + "Failed to clear sense data\n"); + } + + return sd_resume(dev); +} + /** * init_sd - entry point for this driver (both when built in or when * a module).
For SD cardreader devices that have the BLIST_MEDIA_CHANGE flag set, a MEDIA CHANGE unit attention is received after resuming from runtime suspend. Send a REQUEST SENSE to avoid that. The "downside" is that for these devices we now rely on users not to really change the medium (SD card) *during* a runtime suspend/resume cycle, i.e. when not unmounting. To enable runtime PM for an SD cardreader (device 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 Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm> --- drivers/scsi/sd.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)