Messages in this thread | | | Date | Thu, 07 Jan 2021 14:38:53 +0800 | From | Can Guo <> | Subject | Re: [PATCH v3 2/2] scsi: ufs: handle LINERESET with correct tm_cmd |
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On 2021-01-07 05:41, Jaegeuk Kim wrote: > From: Jaegeuk Kim <jaegeuk@google.com> > > 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 <jaegeuk@kernel.org> > --- > 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,
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