The sd_check_event() will be called periodly even when the device is in
the suspended status to check media event. The scsi_test_unit_ready() in
the sd_check_event() will issue scsi cmd request. Issuing scsi request when
the device is in the suspeneded status will cause problem. For example, when
a usb flash disk in the suspended status, scsi_test_unit_ready() issues a
scsi request. The request will be returned as failed because the usb device
is not active. The patch adds scsi_autopm_get_device() and scsi_autopm_put_device()
around scsi_test_unit_ready() in the sd_check_event() to resolve such problem.
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx>
---
drivers/scsi/sd.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
Index: linux-2.6/drivers/scsi/sd.c
===================================================================
--- linux-2.6.orig/drivers/scsi/sd.c
+++ linux-2.6/drivers/scsi/sd.c
@@ -1182,9 +1182,14 @@ static unsigned int sd_check_events(stru
retval = -ENODEV;
if (scsi_block_when_processing_errors(sdp)) {
+ retval = scsi_autopm_get_device(sdp);
+ if (retval)
+ goto out;
+
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
retval = scsi_test_unit_ready(sdp, SD_TIMEOUT, SD_MAX_RETRIES,
sshdr);
+ scsi_autopm_put_device(sdp);
}
/* failed to execute TUR, assume media not present */
--
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