From: Jaegeuk Kim <[email protected]>
This fixes a warning caused by wrong reserve tag usage in __ufshcd_issue_tm_cmd.
WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82 blk_mq_get_tag+0x438/0x46c
And, in ufshcd_err_handler(), we can avoid to send tm_cmd before aborting
outstanding commands by waiting a bit for IO completion like this.
__ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
Signed-off-by: Jaegeuk Kim <[email protected]>
---
drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
1 file changed, 32 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1678cec08b51..47fc8da3cbf9 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -44,6 +44,9 @@
/* Query request timeout */
#define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
+/* LINERESET TIME OUT */
+#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
+
/* Task management command timeout */
#define TM_CMD_TIMEOUT 100 /* msecs */
@@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct *work)
* check if power mode restore is needed.
*/
if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
+ ktime_t start = ktime_get();
+
hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
if (!hba->saved_uic_err)
hba->saved_err &= ~UIC_ERROR;
@@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct *work)
if (ufshcd_is_pwr_mode_restore_needed(hba))
needs_restore = true;
spin_lock_irqsave(hba->host->host_lock, flags);
+ /* Wait for IO completion to avoid aborting IOs */
+ while (hba->outstanding_reqs) {
+ ufshcd_complete_requests(hba);
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
+ schedule();
+ spin_lock_irqsave(hba->host->host_lock, flags);
+ if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
+ LINERESET_IO_TIMEOUT_MS) {
+ dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
+ __func__, hba->outstanding_reqs);
+ break;
+ }
+ }
+
if (!hba->saved_err && !needs_restore)
goto skip_err_handling;
}
@@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
}
- if (enabled_intr_status && retval == IRQ_NONE) {
- dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
- __func__, intr_status);
+ if (enabled_intr_status && retval == IRQ_NONE &&
+ !ufshcd_eh_in_progress(hba)) {
+ dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x, 0x%08x)\n",
+ __func__,
+ intr_status,
+ hba->ufs_stats.last_intr_status,
+ enabled_intr_status);
ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
}
@@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
* Even though we use wait_event() which sleeps indefinitely,
* the maximum wait time is bounded by %TM_CMD_TIMEOUT.
*/
- req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
+ req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
+ BLK_MQ_REQ_NOWAIT);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
req->end_io_data = &wait;
free_slot = req->tag;
WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
@@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
hba->tmf_tag_set = (struct blk_mq_tag_set) {
.nr_hw_queues = 1,
+ .reserved_tags = 1,
.queue_depth = hba->nutmrs,
.ops = &ufshcd_tmf_ops,
.flags = BLK_MQ_F_NO_SCHED,
--
2.29.2.729.g45daf8777d-goog
Hi Jaegeuk,
On 2021-01-07 05:41, Jaegeuk Kim wrote:
> From: Jaegeuk Kim <[email protected]>
>
> This fixes a warning caused by wrong reserve tag usage in
> __ufshcd_issue_tm_cmd.
>
> WARNING: CPU: 7 PID: 7 at block/blk-core.c:630
> blk_get_request+0x68/0x70
> WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
> blk_mq_get_tag+0x438/0x46c
>
> And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
> aborting
> outstanding commands by waiting a bit for IO completion like this.
>
> __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
>
> Signed-off-by: Jaegeuk Kim <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
> 1 file changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 1678cec08b51..47fc8da3cbf9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -44,6 +44,9 @@
> /* Query request timeout */
> #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
>
> +/* LINERESET TIME OUT */
> +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
> +
> /* Task management command timeout */
> #define TM_CMD_TIMEOUT 100 /* msecs */
>
> @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
> *work)
> * check if power mode restore is needed.
> */
> if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
> + ktime_t start = ktime_get();
I don't see the connection btw line-reset and following tmf cmd.
My point is that line-reset is not the only non-fatal error which
leads us to the following tmf cmd. So the wait should be outside
of this check - just put it right before clearing outstanding reqs.
Thanks,
Can Guo.
> +
> hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
> if (!hba->saved_uic_err)
> hba->saved_err &= ~UIC_ERROR;
> @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct
> work_struct *work)
> if (ufshcd_is_pwr_mode_restore_needed(hba))
> needs_restore = true;
> spin_lock_irqsave(hba->host->host_lock, flags);
> + /* Wait for IO completion to avoid aborting IOs */
> + while (hba->outstanding_reqs) {
> + ufshcd_complete_requests(hba);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> + schedule();
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
> + LINERESET_IO_TIMEOUT_MS) {
> + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
> + __func__, hba->outstanding_reqs);
> + break;
> + }
> + }
> +
> if (!hba->saved_err && !needs_restore)
> goto skip_err_handling;
> }
> @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
> *__hba)
> intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> }
>
> - if (enabled_intr_status && retval == IRQ_NONE) {
> - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
> - __func__, intr_status);
> + if (enabled_intr_status && retval == IRQ_NONE &&
> + !ufshcd_eh_in_progress(hba)) {
> + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
> 0x%08x)\n",
> + __func__,
> + intr_status,
> + hba->ufs_stats.last_intr_status,
> + enabled_intr_status);
> ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
> }
>
> @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
> *hba,
> * Even though we use wait_event() which sleeps indefinitely,
> * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> */
> - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
> + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
> + BLK_MQ_REQ_NOWAIT);
> + if (IS_ERR(req))
> + return PTR_ERR(req);
> +
> req->end_io_data = &wait;
> free_slot = req->tag;
> WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
> @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
> __iomem *mmio_base, unsigned int irq)
>
> hba->tmf_tag_set = (struct blk_mq_tag_set) {
> .nr_hw_queues = 1,
> + .reserved_tags = 1,
> .queue_depth = hba->nutmrs,
> .ops = &ufshcd_tmf_ops,
> .flags = BLK_MQ_F_NO_SCHED,
On 2021-01-07 05:41, Jaegeuk Kim wrote:
> From: Jaegeuk Kim <[email protected]>
>
> This fixes a warning caused by wrong reserve tag usage in
> __ufshcd_issue_tm_cmd.
>
> WARNING: CPU: 7 PID: 7 at block/blk-core.c:630
> blk_get_request+0x68/0x70
> WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
> blk_mq_get_tag+0x438/0x46c
>
> And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
> aborting
> outstanding commands by waiting a bit for IO completion like this.
>
> __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
>
Would you mind add a Fixes tag?
> Signed-off-by: Jaegeuk Kim <[email protected]>
> ---
> drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
> 1 file changed, 32 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 1678cec08b51..47fc8da3cbf9 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -44,6 +44,9 @@
> /* Query request timeout */
> #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
>
> +/* LINERESET TIME OUT */
> +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
> +
> /* Task management command timeout */
> #define TM_CMD_TIMEOUT 100 /* msecs */
>
> @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
> *work)
> * check if power mode restore is needed.
> */
> if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
> + ktime_t start = ktime_get();
> +
> hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
> if (!hba->saved_uic_err)
> hba->saved_err &= ~UIC_ERROR;
> @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct
> work_struct *work)
> if (ufshcd_is_pwr_mode_restore_needed(hba))
> needs_restore = true;
> spin_lock_irqsave(hba->host->host_lock, flags);
> + /* Wait for IO completion to avoid aborting IOs */
> + while (hba->outstanding_reqs) {
> + ufshcd_complete_requests(hba);
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> + schedule();
> + spin_lock_irqsave(hba->host->host_lock, flags);
> + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
> + LINERESET_IO_TIMEOUT_MS) {
> + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
> + __func__, hba->outstanding_reqs);
> + break;
> + }
> + }
> +
> if (!hba->saved_err && !needs_restore)
> goto skip_err_handling;
> }
> @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
> *__hba)
> intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> }
>
> - if (enabled_intr_status && retval == IRQ_NONE) {
> - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
> - __func__, intr_status);
> + if (enabled_intr_status && retval == IRQ_NONE &&
> + !ufshcd_eh_in_progress(hba)) {
> + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
> 0x%08x)\n",
> + __func__,
> + intr_status,
> + hba->ufs_stats.last_intr_status,
> + enabled_intr_status);
> ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
> }
>
> @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
> *hba,
> * Even though we use wait_event() which sleeps indefinitely,
> * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> */
> - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
> + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
> + BLK_MQ_REQ_NOWAIT);
Sorry that I didn't pay much attention to this part of code before.
May I know why must we use the BLK_MQ_REQ_RESERVED flag?
Thanks,
Can Guo.
> + if (IS_ERR(req))
> + return PTR_ERR(req);
> +
> req->end_io_data = &wait;
> free_slot = req->tag;
> WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
> @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
> __iomem *mmio_base, unsigned int irq)
>
> hba->tmf_tag_set = (struct blk_mq_tag_set) {
> .nr_hw_queues = 1,
> + .reserved_tags = 1,
If we give reserved_tags as 1 and always ask for a tm requst with
BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated
from the reserved sbitmap_queue, whose depth is set to 1 here.
UFS supports tm queue depth as 8, but here is allowing only one tm
req at a time. Why? Please correct me if my understanding is wrong.
Thanks,
Can Guo.
> .queue_depth = hba->nutmrs,
> .ops = &ufshcd_tmf_ops,
> .flags = BLK_MQ_F_NO_SCHED,
On 01/07, Can Guo wrote:
> On 2021-01-07 05:41, Jaegeuk Kim wrote:
> > From: Jaegeuk Kim <[email protected]>
> >
> > This fixes a warning caused by wrong reserve tag usage in
> > __ufshcd_issue_tm_cmd.
> >
> > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
> > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
> > blk_mq_get_tag+0x438/0x46c
> >
> > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
> > aborting
> > outstanding commands by waiting a bit for IO completion like this.
> >
> > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
> >
>
> Would you mind add a Fixes tag?
Ok.
>
> > Signed-off-by: Jaegeuk Kim <[email protected]>
> > ---
> > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
> > 1 file changed, 32 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 1678cec08b51..47fc8da3cbf9 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -44,6 +44,9 @@
> > /* Query request timeout */
> > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
> >
> > +/* LINERESET TIME OUT */
> > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
> > +
> > /* Task management command timeout */
> > #define TM_CMD_TIMEOUT 100 /* msecs */
> >
> > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
> > *work)
> > * check if power mode restore is needed.
> > */
> > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
> > + ktime_t start = ktime_get();
> > +
> > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
> > if (!hba->saved_uic_err)
> > hba->saved_err &= ~UIC_ERROR;
> > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct
> > *work)
> > if (ufshcd_is_pwr_mode_restore_needed(hba))
> > needs_restore = true;
> > spin_lock_irqsave(hba->host->host_lock, flags);
> > + /* Wait for IO completion to avoid aborting IOs */
> > + while (hba->outstanding_reqs) {
> > + ufshcd_complete_requests(hba);
> > + spin_unlock_irqrestore(hba->host->host_lock, flags);
> > + schedule();
> > + spin_lock_irqsave(hba->host->host_lock, flags);
> > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
> > + LINERESET_IO_TIMEOUT_MS) {
> > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
> > + __func__, hba->outstanding_reqs);
> > + break;
> > + }
> > + }
> > +
> > if (!hba->saved_err && !needs_restore)
> > goto skip_err_handling;
> > }
> > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
> > *__hba)
> > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> > }
> >
> > - if (enabled_intr_status && retval == IRQ_NONE) {
> > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
> > - __func__, intr_status);
> > + if (enabled_intr_status && retval == IRQ_NONE &&
> > + !ufshcd_eh_in_progress(hba)) {
> > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
> > 0x%08x)\n",
> > + __func__,
> > + intr_status,
> > + hba->ufs_stats.last_intr_status,
> > + enabled_intr_status);
> > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
> > }
> >
> > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
> > *hba,
> > * Even though we use wait_event() which sleeps indefinitely,
> > * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> > */
> > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
> > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
> > + BLK_MQ_REQ_NOWAIT);
>
> Sorry that I didn't pay much attention to this part of code before.
> May I know why must we use the BLK_MQ_REQ_RESERVED flag?
What I understood is the reserved tag is used when aborting outstanding
IOs when all the 32 tags were used.
>
> Thanks,
> Can Guo.
>
> > + if (IS_ERR(req))
> > + return PTR_ERR(req);
> > +
> > req->end_io_data = &wait;
> > free_slot = req->tag;
> > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
> > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
> > __iomem *mmio_base, unsigned int irq)
> >
> > hba->tmf_tag_set = (struct blk_mq_tag_set) {
> > .nr_hw_queues = 1,
> > + .reserved_tags = 1,
>
> If we give reserved_tags as 1 and always ask for a tm requst with
> BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated
> from the reserved sbitmap_queue, whose depth is set to 1 here.
> UFS supports tm queue depth as 8, but here is allowing only one tm
> req at a time. Why? Please correct me if my understanding is wrong.
I couldn't find tm can be issued in parallel, so thought it was issued
one at a time. If we set 8, then we can use 24 for IOs, IIUC.
Please correct me as well. I'm still trying to understand the flow.
>
> Thanks,
> Can Guo.
>
> > .queue_depth = hba->nutmrs,
> > .ops = &ufshcd_tmf_ops,
> > .flags = BLK_MQ_F_NO_SCHED,
On 01/07, Can Guo wrote:
> Hi Jaegeuk,
>
> On 2021-01-07 05:41, Jaegeuk Kim wrote:
> > From: Jaegeuk Kim <[email protected]>
> >
> > This fixes a warning caused by wrong reserve tag usage in
> > __ufshcd_issue_tm_cmd.
> >
> > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
> > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
> > blk_mq_get_tag+0x438/0x46c
> >
> > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
> > aborting
> > outstanding commands by waiting a bit for IO completion like this.
> >
> > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
> >
> > Signed-off-by: Jaegeuk Kim <[email protected]>
> > ---
> > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
> > 1 file changed, 32 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 1678cec08b51..47fc8da3cbf9 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -44,6 +44,9 @@
> > /* Query request timeout */
> > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
> >
> > +/* LINERESET TIME OUT */
> > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
> > +
> > /* Task management command timeout */
> > #define TM_CMD_TIMEOUT 100 /* msecs */
> >
> > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
> > *work)
> > * check if power mode restore is needed.
> > */
> > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
> > + ktime_t start = ktime_get();
>
> I don't see the connection btw line-reset and following tmf cmd.
> My point is that line-reset is not the only non-fatal error which
> leads us to the following tmf cmd. So the wait should be outside
> of this check - just put it right before clearing outstanding reqs.
Ok. Let me move it in v4.
>
> Thanks,
> Can Guo.
>
> > +
> > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
> > if (!hba->saved_uic_err)
> > hba->saved_err &= ~UIC_ERROR;
> > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct
> > *work)
> > if (ufshcd_is_pwr_mode_restore_needed(hba))
> > needs_restore = true;
> > spin_lock_irqsave(hba->host->host_lock, flags);
> > + /* Wait for IO completion to avoid aborting IOs */
> > + while (hba->outstanding_reqs) {
> > + ufshcd_complete_requests(hba);
> > + spin_unlock_irqrestore(hba->host->host_lock, flags);
> > + schedule();
> > + spin_lock_irqsave(hba->host->host_lock, flags);
> > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
> > + LINERESET_IO_TIMEOUT_MS) {
> > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
> > + __func__, hba->outstanding_reqs);
> > + break;
> > + }
> > + }
> > +
> > if (!hba->saved_err && !needs_restore)
> > goto skip_err_handling;
> > }
> > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
> > *__hba)
> > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> > }
> >
> > - if (enabled_intr_status && retval == IRQ_NONE) {
> > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
> > - __func__, intr_status);
> > + if (enabled_intr_status && retval == IRQ_NONE &&
> > + !ufshcd_eh_in_progress(hba)) {
> > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
> > 0x%08x)\n",
> > + __func__,
> > + intr_status,
> > + hba->ufs_stats.last_intr_status,
> > + enabled_intr_status);
> > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
> > }
> >
> > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
> > *hba,
> > * Even though we use wait_event() which sleeps indefinitely,
> > * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> > */
> > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
> > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
> > + BLK_MQ_REQ_NOWAIT);
> > + if (IS_ERR(req))
> > + return PTR_ERR(req);
> > +
> > req->end_io_data = &wait;
> > free_slot = req->tag;
> > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
> > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
> > __iomem *mmio_base, unsigned int irq)
> >
> > hba->tmf_tag_set = (struct blk_mq_tag_set) {
> > .nr_hw_queues = 1,
> > + .reserved_tags = 1,
> > .queue_depth = hba->nutmrs,
> > .ops = &ufshcd_tmf_ops,
> > .flags = BLK_MQ_F_NO_SCHED,
On 2021-01-07 14:51, Jaegeuk Kim wrote:
> On 01/07, Can Guo wrote:
>> On 2021-01-07 05:41, Jaegeuk Kim wrote:
>> > From: Jaegeuk Kim <[email protected]>
>> >
>> > This fixes a warning caused by wrong reserve tag usage in
>> > __ufshcd_issue_tm_cmd.
>> >
>> > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
>> > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
>> > blk_mq_get_tag+0x438/0x46c
>> >
>> > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
>> > aborting
>> > outstanding commands by waiting a bit for IO completion like this.
>> >
>> > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
>> >
>>
>> Would you mind add a Fixes tag?
>
> Ok.
>
>>
>> > Signed-off-by: Jaegeuk Kim <[email protected]>
>> > ---
>> > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
>> > 1 file changed, 32 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> > index 1678cec08b51..47fc8da3cbf9 100644
>> > --- a/drivers/scsi/ufs/ufshcd.c
>> > +++ b/drivers/scsi/ufs/ufshcd.c
>> > @@ -44,6 +44,9 @@
>> > /* Query request timeout */
>> > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
>> >
>> > +/* LINERESET TIME OUT */
>> > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
>> > +
>> > /* Task management command timeout */
>> > #define TM_CMD_TIMEOUT 100 /* msecs */
>> >
>> > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
>> > *work)
>> > * check if power mode restore is needed.
>> > */
>> > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
>> > + ktime_t start = ktime_get();
>> > +
>> > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
>> > if (!hba->saved_uic_err)
>> > hba->saved_err &= ~UIC_ERROR;
>> > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct
>> > *work)
>> > if (ufshcd_is_pwr_mode_restore_needed(hba))
>> > needs_restore = true;
>> > spin_lock_irqsave(hba->host->host_lock, flags);
>> > + /* Wait for IO completion to avoid aborting IOs */
>> > + while (hba->outstanding_reqs) {
>> > + ufshcd_complete_requests(hba);
>> > + spin_unlock_irqrestore(hba->host->host_lock, flags);
>> > + schedule();
>> > + spin_lock_irqsave(hba->host->host_lock, flags);
>> > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
>> > + LINERESET_IO_TIMEOUT_MS) {
>> > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
>> > + __func__, hba->outstanding_reqs);
>> > + break;
>> > + }
>> > + }
>> > +
>> > if (!hba->saved_err && !needs_restore)
>> > goto skip_err_handling;
>> > }
>> > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
>> > *__hba)
>> > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
>> > }
>> >
>> > - if (enabled_intr_status && retval == IRQ_NONE) {
>> > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
>> > - __func__, intr_status);
>> > + if (enabled_intr_status && retval == IRQ_NONE &&
>> > + !ufshcd_eh_in_progress(hba)) {
>> > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
>> > 0x%08x)\n",
>> > + __func__,
>> > + intr_status,
>> > + hba->ufs_stats.last_intr_status,
>> > + enabled_intr_status);
>> > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
>> > }
>> >
>> > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
>> > *hba,
>> > * Even though we use wait_event() which sleeps indefinitely,
>> > * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
>> > */
>> > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
>> > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
>> > + BLK_MQ_REQ_NOWAIT);
>>
>> Sorry that I didn't pay much attention to this part of code before.
>> May I know why must we use the BLK_MQ_REQ_RESERVED flag?
>
> What I understood is the reserved tag is used when aborting outstanding
> IOs when all the 32 tags were used.
>
No, the tm requests and I/O requests are on two different tag sets:
tm requests come from hba->tmf_tag_set, while I/O requests come from
hba->shost->tag_set. Meaning they don't share tags with each other.
>>
>> Thanks,
>> Can Guo.
>>
>> > + if (IS_ERR(req))
>> > + return PTR_ERR(req);
>> > +
>> > req->end_io_data = &wait;
>> > free_slot = req->tag;
>> > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
>> > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
>> > __iomem *mmio_base, unsigned int irq)
>> >
>> > hba->tmf_tag_set = (struct blk_mq_tag_set) {
>> > .nr_hw_queues = 1,
>> > + .reserved_tags = 1,
>>
>> If we give reserved_tags as 1 and always ask for a tm requst with
>> BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated
>> from the reserved sbitmap_queue, whose depth is set to 1 here.
>> UFS supports tm queue depth as 8, but here is allowing only one tm
>> req at a time. Why? Please correct me if my understanding is wrong.
>
> I couldn't find tm can be issued in parallel, so thought it was issued
> one at a time. If we set 8, then we can use 24 for IOs, IIUC.
>
> Please correct me as well. I'm still trying to understand the flow.
>
UFS allows a queue depth as 8, which means it support sending multiple
tm requests at the same time. You can check commit 69a6c269c097d780a2 -
before this change, we used to use below func to allocate tags for
tm reqs, which can tell you the true story.
So I am thinking why don't we just we remove the BLK_MQ_REQ_RESERVED
flag?
Removing it can also fix the warning I suppose. What do you think?
-static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int
*free_slot)
-{
- int tag;
- bool ret = false;
-
- if (!free_slot)
- goto out;
-
- do {
- tag = find_first_zero_bit(&hba->tm_slots_in_use,
hba->nutmrs);
- if (tag >= hba->nutmrs)
- goto out;
- } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
-
- *free_slot = tag;
- ret = true;
-out:
- return ret;
-}
Thanks,
Can Guo.
>>
>> Thanks,
>> Can Guo.
>>
>> > .queue_depth = hba->nutmrs,
>> > .ops = &ufshcd_tmf_ops,
>> > .flags = BLK_MQ_F_NO_SCHED,
On 2021-01-07 15:03, Can Guo wrote:
> On 2021-01-07 14:51, Jaegeuk Kim wrote:
>> On 01/07, Can Guo wrote:
>>> On 2021-01-07 05:41, Jaegeuk Kim wrote:
>>> > From: Jaegeuk Kim <[email protected]>
>>> >
>>> > This fixes a warning caused by wrong reserve tag usage in
>>> > __ufshcd_issue_tm_cmd.
>>> >
>>> > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
>>> > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
>>> > blk_mq_get_tag+0x438/0x46c
>>> >
>>> > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
>>> > aborting
>>> > outstanding commands by waiting a bit for IO completion like this.
>>> >
>>> > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
>>> >
>>>
>>> Would you mind add a Fixes tag?
>>
>> Ok.
>>
>>>
>>> > Signed-off-by: Jaegeuk Kim <[email protected]>
>>> > ---
>>> > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
>>> > 1 file changed, 32 insertions(+), 4 deletions(-)
>>> >
>>> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>>> > index 1678cec08b51..47fc8da3cbf9 100644
>>> > --- a/drivers/scsi/ufs/ufshcd.c
>>> > +++ b/drivers/scsi/ufs/ufshcd.c
>>> > @@ -44,6 +44,9 @@
>>> > /* Query request timeout */
>>> > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
>>> >
>>> > +/* LINERESET TIME OUT */
>>> > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
>>> > +
>>> > /* Task management command timeout */
>>> > #define TM_CMD_TIMEOUT 100 /* msecs */
>>> >
>>> > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
>>> > *work)
>>> > * check if power mode restore is needed.
>>> > */
>>> > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
>>> > + ktime_t start = ktime_get();
>>> > +
>>> > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
>>> > if (!hba->saved_uic_err)
>>> > hba->saved_err &= ~UIC_ERROR;
>>> > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct
>>> > *work)
>>> > if (ufshcd_is_pwr_mode_restore_needed(hba))
>>> > needs_restore = true;
>>> > spin_lock_irqsave(hba->host->host_lock, flags);
>>> > + /* Wait for IO completion to avoid aborting IOs */
>>> > + while (hba->outstanding_reqs) {
>>> > + ufshcd_complete_requests(hba);
>>> > + spin_unlock_irqrestore(hba->host->host_lock, flags);
>>> > + schedule();
>>> > + spin_lock_irqsave(hba->host->host_lock, flags);
>>> > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
>>> > + LINERESET_IO_TIMEOUT_MS) {
>>> > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
>>> > + __func__, hba->outstanding_reqs);
>>> > + break;
>>> > + }
>>> > + }
>>> > +
>>> > if (!hba->saved_err && !needs_restore)
>>> > goto skip_err_handling;
>>> > }
>>> > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
>>> > *__hba)
>>> > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
>>> > }
>>> >
>>> > - if (enabled_intr_status && retval == IRQ_NONE) {
>>> > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
>>> > - __func__, intr_status);
>>> > + if (enabled_intr_status && retval == IRQ_NONE &&
>>> > + !ufshcd_eh_in_progress(hba)) {
>>> > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
>>> > 0x%08x)\n",
>>> > + __func__,
>>> > + intr_status,
>>> > + hba->ufs_stats.last_intr_status,
>>> > + enabled_intr_status);
>>> > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
>>> > }
>>> >
>>> > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
>>> > *hba,
>>> > * Even though we use wait_event() which sleeps indefinitely,
>>> > * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
>>> > */
>>> > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
>>> > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
>>> > + BLK_MQ_REQ_NOWAIT);
>>>
>>> Sorry that I didn't pay much attention to this part of code before.
>>> May I know why must we use the BLK_MQ_REQ_RESERVED flag?
>>
>> What I understood is the reserved tag is used when aborting
>> outstanding
>> IOs when all the 32 tags were used.
>>
>
> No, the tm requests and I/O requests are on two different tag sets:
> tm requests come from hba->tmf_tag_set, while I/O requests come from
> hba->shost->tag_set. Meaning they don't share tags with each other.
Add they are issued on two different HW queues - one for tm reqs,
one for I/O reqs, which is why two different tag sets are created.
>
>>>
>>> Thanks,
>>> Can Guo.
>>>
>>> > + if (IS_ERR(req))
>>> > + return PTR_ERR(req);
>>> > +
>>> > req->end_io_data = &wait;
>>> > free_slot = req->tag;
>>> > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
>>> > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
>>> > __iomem *mmio_base, unsigned int irq)
>>> >
>>> > hba->tmf_tag_set = (struct blk_mq_tag_set) {
>>> > .nr_hw_queues = 1,
>>> > + .reserved_tags = 1,
>>>
>>> If we give reserved_tags as 1 and always ask for a tm requst with
>>> BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated
>>> from the reserved sbitmap_queue, whose depth is set to 1 here.
>>> UFS supports tm queue depth as 8, but here is allowing only one tm
>>> req at a time. Why? Please correct me if my understanding is wrong.
>>
>> I couldn't find tm can be issued in parallel, so thought it was issued
>> one at a time. If we set 8, then we can use 24 for IOs, IIUC.
>>
>> Please correct me as well. I'm still trying to understand the flow.
>>
>
> UFS allows a queue depth as 8, which means it support sending multiple
> tm requests at the same time. You can check commit 69a6c269c097d780a2 -
> before this change, we used to use below func to allocate tags for
> tm reqs, which can tell you the true story.
>
> So I am thinking why don't we just we remove the BLK_MQ_REQ_RESERVED
> flag?
> Removing it can also fix the warning I suppose. What do you think?
>
> -static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int
> *free_slot)
> -{
> - int tag;
> - bool ret = false;
> -
> - if (!free_slot)
> - goto out;
> -
> - do {
> - tag = find_first_zero_bit(&hba->tm_slots_in_use,
> hba->nutmrs);
> - if (tag >= hba->nutmrs)
> - goto out;
> - } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
> -
> - *free_slot = tag;
> - ret = true;
> -out:
> - return ret;
> -}
>
> Thanks,
> Can Guo.
>
>>>
>>> Thanks,
>>> Can Guo.
>>>
>>> > .queue_depth = hba->nutmrs,
>>> > .ops = &ufshcd_tmf_ops,
>>> > .flags = BLK_MQ_F_NO_SCHED,
On 01/07, Can Guo wrote:
> On 2021-01-07 14:51, Jaegeuk Kim wrote:
> > On 01/07, Can Guo wrote:
> > > On 2021-01-07 05:41, Jaegeuk Kim wrote:
> > > > From: Jaegeuk Kim <[email protected]>
> > > >
> > > > This fixes a warning caused by wrong reserve tag usage in
> > > > __ufshcd_issue_tm_cmd.
> > > >
> > > > WARNING: CPU: 7 PID: 7 at block/blk-core.c:630 blk_get_request+0x68/0x70
> > > > WARNING: CPU: 4 PID: 157 at block/blk-mq-tag.c:82
> > > > blk_mq_get_tag+0x438/0x46c
> > > >
> > > > And, in ufshcd_err_handler(), we can avoid to send tm_cmd before
> > > > aborting
> > > > outstanding commands by waiting a bit for IO completion like this.
> > > >
> > > > __ufshcd_issue_tm_cmd: task management cmd 0x80 timed-out
> > > >
> > >
> > > Would you mind add a Fixes tag?
> >
> > Ok.
> >
> > >
> > > > Signed-off-by: Jaegeuk Kim <[email protected]>
> > > > ---
> > > > drivers/scsi/ufs/ufshcd.c | 36 ++++++++++++++++++++++++++++++++----
> > > > 1 file changed, 32 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > > > index 1678cec08b51..47fc8da3cbf9 100644
> > > > --- a/drivers/scsi/ufs/ufshcd.c
> > > > +++ b/drivers/scsi/ufs/ufshcd.c
> > > > @@ -44,6 +44,9 @@
> > > > /* Query request timeout */
> > > > #define QUERY_REQ_TIMEOUT 1500 /* 1.5 seconds */
> > > >
> > > > +/* LINERESET TIME OUT */
> > > > +#define LINERESET_IO_TIMEOUT_MS (30000) /* 30 sec */
> > > > +
> > > > /* Task management command timeout */
> > > > #define TM_CMD_TIMEOUT 100 /* msecs */
> > > >
> > > > @@ -5899,6 +5902,8 @@ static void ufshcd_err_handler(struct work_struct
> > > > *work)
> > > > * check if power mode restore is needed.
> > > > */
> > > > if (hba->saved_uic_err & UFSHCD_UIC_PA_GENERIC_ERROR) {
> > > > + ktime_t start = ktime_get();
> > > > +
> > > > hba->saved_uic_err &= ~UFSHCD_UIC_PA_GENERIC_ERROR;
> > > > if (!hba->saved_uic_err)
> > > > hba->saved_err &= ~UIC_ERROR;
> > > > @@ -5906,6 +5911,20 @@ static void ufshcd_err_handler(struct work_struct
> > > > *work)
> > > > if (ufshcd_is_pwr_mode_restore_needed(hba))
> > > > needs_restore = true;
> > > > spin_lock_irqsave(hba->host->host_lock, flags);
> > > > + /* Wait for IO completion to avoid aborting IOs */
> > > > + while (hba->outstanding_reqs) {
> > > > + ufshcd_complete_requests(hba);
> > > > + spin_unlock_irqrestore(hba->host->host_lock, flags);
> > > > + schedule();
> > > > + spin_lock_irqsave(hba->host->host_lock, flags);
> > > > + if (ktime_to_ms(ktime_sub(ktime_get(), start)) >
> > > > + LINERESET_IO_TIMEOUT_MS) {
> > > > + dev_err(hba->dev, "%s: timeout, outstanding=0x%lx\n",
> > > > + __func__, hba->outstanding_reqs);
> > > > + break;
> > > > + }
> > > > + }
> > > > +
> > > > if (!hba->saved_err && !needs_restore)
> > > > goto skip_err_handling;
> > > > }
> > > > @@ -6302,9 +6321,13 @@ static irqreturn_t ufshcd_intr(int irq, void
> > > > *__hba)
> > > > intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
> > > > }
> > > >
> > > > - if (enabled_intr_status && retval == IRQ_NONE) {
> > > > - dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x\n",
> > > > - __func__, intr_status);
> > > > + if (enabled_intr_status && retval == IRQ_NONE &&
> > > > + !ufshcd_eh_in_progress(hba)) {
> > > > + dev_err(hba->dev, "%s: Unhandled interrupt 0x%08x (0x%08x,
> > > > 0x%08x)\n",
> > > > + __func__,
> > > > + intr_status,
> > > > + hba->ufs_stats.last_intr_status,
> > > > + enabled_intr_status);
> > > > ufshcd_dump_regs(hba, 0, UFSHCI_REG_SPACE_SIZE, "host_regs: ");
> > > > }
> > > >
> > > > @@ -6348,7 +6371,11 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba
> > > > *hba,
> > > > * Even though we use wait_event() which sleeps indefinitely,
> > > > * the maximum wait time is bounded by %TM_CMD_TIMEOUT.
> > > > */
> > > > - req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
> > > > + req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED |
> > > > + BLK_MQ_REQ_NOWAIT);
> > >
> > > Sorry that I didn't pay much attention to this part of code before.
> > > May I know why must we use the BLK_MQ_REQ_RESERVED flag?
> >
> > What I understood is the reserved tag is used when aborting outstanding
> > IOs when all the 32 tags were used.
> >
>
> No, the tm requests and I/O requests are on two different tag sets:
> tm requests come from hba->tmf_tag_set, while I/O requests come from
> hba->shost->tag_set. Meaning they don't share tags with each other.
I see. :)
>
> > >
> > > Thanks,
> > > Can Guo.
> > >
> > > > + if (IS_ERR(req))
> > > > + return PTR_ERR(req);
> > > > +
> > > > req->end_io_data = &wait;
> > > > free_slot = req->tag;
> > > > WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
> > > > @@ -9355,6 +9382,7 @@ int ufshcd_init(struct ufs_hba *hba, void
> > > > __iomem *mmio_base, unsigned int irq)
> > > >
> > > > hba->tmf_tag_set = (struct blk_mq_tag_set) {
> > > > .nr_hw_queues = 1,
> > > > + .reserved_tags = 1,
> > >
> > > If we give reserved_tags as 1 and always ask for a tm requst with
> > > BLK_MQ_REQ_RESERVED flag set, then the tag shall only be allocated
> > > from the reserved sbitmap_queue, whose depth is set to 1 here.
> > > UFS supports tm queue depth as 8, but here is allowing only one tm
> > > req at a time. Why? Please correct me if my understanding is wrong.
> >
> > I couldn't find tm can be issued in parallel, so thought it was issued
> > one at a time. If we set 8, then we can use 24 for IOs, IIUC.
> >
> > Please correct me as well. I'm still trying to understand the flow.
> >
>
> UFS allows a queue depth as 8, which means it support sending multiple
> tm requests at the same time. You can check commit 69a6c269c097d780a2 -
> before this change, we used to use below func to allocate tags for
> tm reqs, which can tell you the true story.
>
> So I am thinking why don't we just we remove the BLK_MQ_REQ_RESERVED flag?
> Removing it can also fix the warning I suppose. What do you think?
Yeah, I believe it won't give a warning. Okay, let me check it out.
>
> -static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int *free_slot)
> -{
> - int tag;
> - bool ret = false;
> -
> - if (!free_slot)
> - goto out;
> -
> - do {
> - tag = find_first_zero_bit(&hba->tm_slots_in_use,
> hba->nutmrs);
> - if (tag >= hba->nutmrs)
> - goto out;
> - } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
> -
> - *free_slot = tag;
> - ret = true;
> -out:
> - return ret;
> -}
>
> Thanks,
> Can Guo.
>
> > >
> > > Thanks,
> > > Can Guo.
> > >
> > > > .queue_depth = hba->nutmrs,
> > > > .ops = &ufshcd_tmf_ops,
> > > > .flags = BLK_MQ_F_NO_SCHED,