* [PATCH v2] scsi: ufs: Fix the polling implementation
@ 2022-11-18 23:37 Bart Van Assche
2022-11-21 13:48 ` Adrian Hunter
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Bart Van Assche @ 2022-11-18 23:37 UTC (permalink / raw)
To: Martin K . Petersen
Cc: Jaegeuk Kim, linux-scsi, Adrian Hunter, Bart Van Assche,
James E.J. Bottomley, Bean Huo, Avri Altman, Jinyoung Choi
Fix the following issues in ufshcd_poll():
- If polling succeeds, return a positive value.
- Do not complete polling requests from interrupt context because the
block layer expects these requests to be completed from thread
context. From block/bio.c:
If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done
from process context, not hard/soft IRQ.
Fixes: eaab9b573054 ("scsi: ufs: Implement polling support")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
Changes compared to v1:
- Made sure that polled requests are not completed from interrupt context.
drivers/ufs/core/ufshcd.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 768cb49d269c..b4bf3c3bef0c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -5344,6 +5344,26 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
}
}
+/* Any value that is not an existing queue number is fine for this constant. */
+enum {
+ UFSHCD_POLL_FROM_INTERRUPT_CONTEXT = -1
+};
+
+static void ufshcd_clear_polled(struct ufs_hba *hba,
+ unsigned long *completed_reqs)
+{
+ int tag;
+
+ for_each_set_bit(tag, completed_reqs, hba->nutrs) {
+ struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
+
+ if (!cmd)
+ continue;
+ if (scsi_cmd_to_rq(cmd)->cmd_flags & REQ_POLLED)
+ __clear_bit(tag, completed_reqs);
+ }
+}
+
/*
* Returns > 0 if one or more commands have been completed or 0 if no
* requests have been completed.
@@ -5360,13 +5380,17 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
WARN_ONCE(completed_reqs & ~hba->outstanding_reqs,
"completed: %#lx; outstanding: %#lx\n", completed_reqs,
hba->outstanding_reqs);
+ if (queue_num == UFSHCD_POLL_FROM_INTERRUPT_CONTEXT) {
+ /* Do not complete polled requests from interrupt context. */
+ ufshcd_clear_polled(hba, &completed_reqs);
+ }
hba->outstanding_reqs &= ~completed_reqs;
spin_unlock_irqrestore(&hba->outstanding_lock, flags);
if (completed_reqs)
__ufshcd_transfer_req_compl(hba, completed_reqs);
- return completed_reqs;
+ return completed_reqs != 0;
}
/**
@@ -5397,7 +5421,7 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
* Ignore the ufshcd_poll() return value and return IRQ_HANDLED since we
* do not want polling to trigger spurious interrupt complaints.
*/
- ufshcd_poll(hba->host, 0);
+ ufshcd_poll(hba->host, UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
return IRQ_HANDLED;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: ufs: Fix the polling implementation
2022-11-18 23:37 [PATCH v2] scsi: ufs: Fix the polling implementation Bart Van Assche
@ 2022-11-21 13:48 ` Adrian Hunter
2022-11-26 2:31 ` Martin K. Petersen
2022-12-01 3:45 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Adrian Hunter @ 2022-11-21 13:48 UTC (permalink / raw)
To: Bart Van Assche, Martin K . Petersen
Cc: Jaegeuk Kim, linux-scsi, James E.J. Bottomley, Bean Huo,
Avri Altman, Jinyoung Choi
On 19/11/22 01:37, Bart Van Assche wrote:
> Fix the following issues in ufshcd_poll():
> - If polling succeeds, return a positive value.
> - Do not complete polling requests from interrupt context because the
> block layer expects these requests to be completed from thread
> context. From block/bio.c:
>
> If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done
> from process context, not hard/soft IRQ.
>
> Fixes: eaab9b573054 ("scsi: ufs: Implement polling support")
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>
> Changes compared to v1:
> - Made sure that polled requests are not completed from interrupt context.
>
> drivers/ufs/core/ufshcd.c | 28 ++++++++++++++++++++++++++--
> 1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index 768cb49d269c..b4bf3c3bef0c 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -5344,6 +5344,26 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
> }
> }
>
> +/* Any value that is not an existing queue number is fine for this constant. */
> +enum {
> + UFSHCD_POLL_FROM_INTERRUPT_CONTEXT = -1
> +};
> +
> +static void ufshcd_clear_polled(struct ufs_hba *hba,
> + unsigned long *completed_reqs)
> +{
> + int tag;
> +
> + for_each_set_bit(tag, completed_reqs, hba->nutrs) {
> + struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
> +
> + if (!cmd)
> + continue;
> + if (scsi_cmd_to_rq(cmd)->cmd_flags & REQ_POLLED)
> + __clear_bit(tag, completed_reqs);
> + }
> +}
> +
> /*
> * Returns > 0 if one or more commands have been completed or 0 if no
> * requests have been completed.
> @@ -5360,13 +5380,17 @@ static int ufshcd_poll(struct Scsi_Host *shost, unsigned int queue_num)
> WARN_ONCE(completed_reqs & ~hba->outstanding_reqs,
> "completed: %#lx; outstanding: %#lx\n", completed_reqs,
> hba->outstanding_reqs);
> + if (queue_num == UFSHCD_POLL_FROM_INTERRUPT_CONTEXT) {
> + /* Do not complete polled requests from interrupt context. */
> + ufshcd_clear_polled(hba, &completed_reqs);
> + }
> hba->outstanding_reqs &= ~completed_reqs;
> spin_unlock_irqrestore(&hba->outstanding_lock, flags);
>
> if (completed_reqs)
> __ufshcd_transfer_req_compl(hba, completed_reqs);
>
> - return completed_reqs;
> + return completed_reqs != 0;
> }
>
> /**
> @@ -5397,7 +5421,7 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
> * Ignore the ufshcd_poll() return value and return IRQ_HANDLED since we
> * do not want polling to trigger spurious interrupt complaints.
> */
> - ufshcd_poll(hba->host, 0);
> + ufshcd_poll(hba->host, UFSHCD_POLL_FROM_INTERRUPT_CONTEXT);
>
> return IRQ_HANDLED;
> }
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: ufs: Fix the polling implementation
2022-11-18 23:37 [PATCH v2] scsi: ufs: Fix the polling implementation Bart Van Assche
2022-11-21 13:48 ` Adrian Hunter
@ 2022-11-26 2:31 ` Martin K. Petersen
2022-12-01 3:45 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2022-11-26 2:31 UTC (permalink / raw)
To: Bart Van Assche
Cc: Martin K . Petersen, Jaegeuk Kim, linux-scsi, Adrian Hunter,
James E.J. Bottomley, Bean Huo, Avri Altman, Jinyoung Choi
Bart,
> Fix the following issues in ufshcd_poll():
> - If polling succeeds, return a positive value.
> - Do not complete polling requests from interrupt context because the
> block layer expects these requests to be completed from thread
> context. From block/bio.c:
Applied to 6.2/scsi-staging, thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] scsi: ufs: Fix the polling implementation
2022-11-18 23:37 [PATCH v2] scsi: ufs: Fix the polling implementation Bart Van Assche
2022-11-21 13:48 ` Adrian Hunter
2022-11-26 2:31 ` Martin K. Petersen
@ 2022-12-01 3:45 ` Martin K. Petersen
2 siblings, 0 replies; 4+ messages in thread
From: Martin K. Petersen @ 2022-12-01 3:45 UTC (permalink / raw)
To: Bart Van Assche
Cc: Martin K . Petersen, Jaegeuk Kim, Adrian Hunter, Jinyoung Choi,
linux-scsi, Bean Huo, James E.J. Bottomley, Avri Altman
On Fri, 18 Nov 2022 15:37:03 -0800, Bart Van Assche wrote:
> Fix the following issues in ufshcd_poll():
> - If polling succeeds, return a positive value.
> - Do not complete polling requests from interrupt context because the
> block layer expects these requests to be completed from thread
> context. From block/bio.c:
>
> If REQ_ALLOC_CACHE is set, the final put of the bio MUST be done
> from process context, not hard/soft IRQ.
>
> [...]
Applied to 6.2/scsi-queue, thanks!
[1/1] scsi: ufs: Fix the polling implementation
https://git.kernel.org/mkp/scsi/c/ee8c88cab4af
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-11-21 13:48 ` Adrian Hunter
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2022-12-01 3:45 ` Martin K. Petersen
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