Re: [PATCH V2] scsi: ufs-pci: Add LTR support for Intel controllers

From: Adrian Hunter
Date: Wed Sep 09 2020 - 11:41:14 EST


On 2/09/20 12:27 pm, Adrian Hunter wrote:
> On 2/09/20 5:12 am, Martin K. Petersen wrote:
>>
>> Adrian,
>>
>>> Intel host controllers support the setting of latency tolerance.
>>> Accordingly, implement the PM QoS ->set_latency_tolerance() callback. The
>>> raw register values are also exposed via debugfs.
>>
>> Does not apply to 5.10/scsi-queue. Please rebase. Thanks!
>>
>
> Hi
>
> Thanks for processing this.
>
> The 5.10/scsi-queue branch seems to be missing the following fix. If you cherry
> pick that, then it applies.

Now there seem to be conflicts between 5.10/scsi-queue and v5.9-rc4.
I am not sure what I can do?


~/git/scsi-mkp$ git branch -v --list 5.10/scsi-queue
* 5.10/scsi-queue 2e9defc7e918 [ahead 427, behind 97] scsi: ufs: Fix a race condition between error handler and runtime PM ops
~/git/scsi-mkp$ git rebase --onto v5.9-rc4 v5.9-rc1
First, rewinding head to replay your work on top of it...
Applying: scsi: ufs: Add checks before setting clk-gating states
Applying: scsi: ufs: ufs-qcom: Fix race conditions caused by ufs_qcom_testbus_config()
Applying: scsi: ufs-qcom: Remove testbus dump in ufs_qcom_dump_dbg_regs
Applying: scsi: ufs: Add some debug information to ufshcd_print_host_state()
Applying: scsi: ufs: Fix concurrency of error handler and other error recovery paths
Applying: scsi: ufs: Recover HBA runtime PM error in error handler
Applying: scsi: ufs: Move dumps in IRQ handler to error handler
Applying: scsi: ufs: Fix a race condition between error handler and runtime PM ops
Applying: scsi: ufs: Properly release resources if a task is aborted successfully
Using index info to reconstruct a base tree...
M drivers/scsi/ufs/ufshcd.c
Falling back to patching base and 3-way merge...
Auto-merging drivers/scsi/ufs/ufshcd.c
CONFLICT (content): Merge conflict in drivers/scsi/ufs/ufshcd.c
error: Failed to merge in the changes.
Patch failed at 0009 scsi: ufs: Properly release resources if a task is aborted successfully
Use 'git am --show-current-patch' to see the failed patch

Resolve all conflicts manually, mark them as resolved with
"git add/rm <conflicted_files>", then run "git rebase --continue".
You can instead skip this commit: run "git rebase --skip".
To abort and get back to the state before "git rebase", run "git rebase --abort".

~/git/scsi-mkp$ git diff
diff --cc drivers/scsi/ufs/ufshcd.c
index d9386f85c255,efb40b1b95b4..000000000000
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@@ -6640,12 -6636,8 +6640,14 @@@ static int ufshcd_abort(struct scsi_cmn
goto out;
}

++<<<<<<< HEAD
+cleanup:
+ scsi_dma_unmap(cmd);
+
++=======
++>>>>>>> scsi: ufs: Properly release resources if a task is aborted successfully
spin_lock_irqsave(host->host_lock, flags);
- ufshcd_outstanding_req_clear(hba, tag);
- hba->lrb[tag].cmd = NULL;
+ __ufshcd_transfer_req_compl(hba, (1UL << tag));
spin_unlock_irqrestore(host->host_lock, flags);

out:

~/git/scsi-mkp$ git am --show-current-patch | head -25
commit 8bb2dde069d860e7ea379862a7d0e8ee01cec5e9
Author: Can Guo <cang@xxxxxxxxxxxxxx>
Date: Sun Aug 9 05:15:55 2020 -0700

scsi: ufs: Properly release resources if a task is aborted successfully

In current UFS task abort hook, namely ufshcd_abort(), if one task is
aborted successfully, clk_gating.active_reqs held by this task is not
decreased, which makes clk_gating.active_reqs stay above zero forever, thus
clock gating would never happen. Instead of releasing resources of one task
"manually", use the existing func __ufshcd_transfer_req_compl(). This
change also eliminates a possible race of scsi_dma_unmap() from the real
completion in IRQ handler path.

Link: https://lore.kernel.org/r/1596975355-39813-10-git-send-email-cang@xxxxxxxxxxxxxx
Fixes: 1ab27c9cf8b6 ("ufs: Add support for clock gating")
CC: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Reviewed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>