From: Martin Kepplinger <martin.kepplinger@puri.sm>
To: martin.kepplinger@puri.sm, bvanassche@acm.org
Cc: jejb@linux.ibm.com, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, linux-scsi@vger.kernel.org,
martin.petersen@oracle.com, kernel@puri.sm,
stern@rowland.harvard.edu
Subject: [PATCH v5 2/3] scsi: sd: send REQUEST SENSE for BLIST_MEDIA_CHANGE devices in runtime_resume()
Date: Wed, 30 Jun 2021 10:44:52 +0200 [thread overview]
Message-ID: <20210630084453.186764-3-martin.kepplinger@puri.sm> (raw)
In-Reply-To: <20210630084453.186764-1-martin.kepplinger@puri.sm>
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(-)
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).
--
2.30.2
next prev parent reply other threads:[~2021-06-30 8:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-30 8:44 [PATCH v5 0/3] fix runtime PM for SD card readers Martin Kepplinger
2021-06-30 8:44 ` [PATCH v5 1/3] scsi: devinfo: add new flag BLIST_MEDIA_CHANGE Martin Kepplinger
2021-06-30 8:44 ` Martin Kepplinger [this message]
2021-07-01 14:35 ` [PATCH v5 2/3] scsi: sd: send REQUEST SENSE for BLIST_MEDIA_CHANGE devices in runtime_resume() Bart Van Assche
2021-07-01 14:49 ` Christoph Hellwig
2021-07-02 8:04 ` Martin Kepplinger
2021-07-02 13:43 ` Bart Van Assche
2021-06-30 8:44 ` [PATCH v5 3/3] scsi: devinfo: add BLIST_MEDIA_CHANGE for Ultra HS-SD/MMC usb cardreaders Martin Kepplinger
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