On 3/31/2021 11:19 AM, Adrian Hunter wrote:
On 31/03/21 1:31 am, Asutosh Das wrote:
During runtime-suspend of ufs host, the scsi devices are
already suspended and so are the queues associated with them.
But the ufs host sends SSU (START_STOP_UNIT) to wlun
during its runtime-suspend.
During the process blk_queue_enter checks if the queue is not in
suspended state. If so, it waits for the queue to resume, and never
comes out of it.
The commit
(d55d15a33: scsi: block: Do not accept any requests while suspended)
adds the check if the queue is in suspended state in blk_queue_enter().
Call trace:
__switch_to+0x174/0x2c4
__schedule+0x478/0x764
schedule+0x9c/0xe0
blk_queue_enter+0x158/0x228
blk_mq_alloc_request+0x40/0xa4
blk_get_request+0x2c/0x70
__scsi_execute+0x60/0x1c4
ufshcd_set_dev_pwr_mode+0x124/0x1e4
ufshcd_suspend+0x208/0x83c
ufshcd_runtime_suspend+0x40/0x154
ufshcd_pltfrm_runtime_suspend+0x14/0x20
pm_generic_runtime_suspend+0x28/0x3c
__rpm_callback+0x80/0x2a4
rpm_suspend+0x308/0x614
rpm_idle+0x158/0x228
pm_runtime_work+0x84/0xac
process_one_work+0x1f0/0x470
worker_thread+0x26c/0x4c8
kthread+0x13c/0x320
ret_from_fork+0x10/0x18
Fix this by registering ufs device wlun as a scsi driver and
registering it for block runtime-pm. Also make this as a
supplier for all other luns. That way, this device wlun
suspends after all the consumers and resumes after
hba resumes.
Co-developed-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
---
Hi Adrian
Thanks for the comments.
Looks good but still doesn't seem to based on the latest tree.
Umm, it's based on the below:
git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git
Branch: refs/heads/for-next
The top most change is e27f3c8 on 27th March'21.
Which tree are you referring to that'd be latest?
Also came across the issue below:
<SNIP>
+#ifdef CONFIG_PM_SLEEP
+static int ufshcd_wl_poweroff(struct device *dev)
+{
+ ufshcd_wl_shutdown(dev);
This turned out to be wrong. This is a PM op and SCSI has already
quiesced the sdev's. All that is needed isOk. I'll fix it in the next version.
__ufshcd_wl_suspend(hba, UFS_SHUTDOWN_PM);
+ return 0;
+}
+#endif
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