diff mbox series

[v3] ufs: core: ufshcd: use local_clock() for debugging timestamps

Message ID 20220802103230.v3.1.I699244ea7efbd326a34a6dfd9b5a31e78400cf68@changeid
State Superseded
Headers show
Series [v3] ufs: core: ufshcd: use local_clock() for debugging timestamps | expand

Commit Message

Daniil Lunev Aug. 2, 2022, 12:32 a.m. UTC
CLOCK_MONOTONIC is not advanced when the system is in suspend. This
becomes problematic when debugging issues related to suspend-resume:
the timestamps printed by ufshcd_print_trs can not be correlated with
dmesg entries, which are timestamped with local_clock().

This CL changes the used clock to local_clock() for the informational
timestamp variables and adds mirroring *_local_clock instances for
variables used in subsequent derevations (to not change the semantics of
those derevations).

Signed-off-by: Daniil Lunev <dlunev@chromium.org>

---

Changes in v3:
- Add missing header

Changes in v2:
- Use local clock to better align with dmesg
- Correct commit message

 drivers/ufs/core/ufshcd.c | 20 ++++++++++++--------
 include/ufs/ufshcd.h      | 14 +++++++++-----
 2 files changed, 21 insertions(+), 13 deletions(-)

Comments

Avri Altman Aug. 2, 2022, 7:18 a.m. UTC | #1
> CLOCK_MONOTONIC is not advanced when the system is in suspend. This
> becomes problematic when debugging issues related to suspend-resume:
> the timestamps printed by ufshcd_print_trs can not be correlated with dmesg
> entries, which are timestamped with local_clock().
> 
> This CL changes the used clock to local_clock() for the informational timestamp
> variables and adds mirroring *_local_clock instances for variables used in
> subsequent derevations (to not change the semantics of those derevations).
I agree with this approach because the words of cautious while using sched_clock()
Happens to be true for various ufs platforms, specifically of a required stabilization period.

Acked-by: Avri Altman <avri.altman@wdc.com> 

> 
> Signed-off-by: Daniil Lunev <dlunev@chromium.org>
> 
> ---
> 
> Changes in v3:
> - Add missing header
> 
> Changes in v2:
> - Use local clock to better align with dmesg
> - Correct commit message
> 
>  drivers/ufs/core/ufshcd.c | 20 ++++++++++++--------
>  include/ufs/ufshcd.h      | 14 +++++++++-----
>  2 files changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index
> ce86d1b790c05..e61dafb93986f 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -21,6 +21,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/module.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/sched/clock.h>
>  #include <scsi/scsi_cmnd.h>
>  #include <scsi/scsi_dbg.h>
>  #include <scsi/scsi_driver.h>
> @@ -460,7 +461,7 @@ static void ufshcd_print_evt(struct ufs_hba *hba, u32 id,
>                 if (e->tstamp[p] == 0)
>                         continue;
>                 dev_err(hba->dev, "%s[%d] = 0x%x at %lld us\n", err_name, p,
> -                       e->val[p], ktime_to_us(e->tstamp[p]));
> +                       e->val[p], e->tstamp[p] / 1000);
>                 found = true;
>         }
> 
> @@ -505,9 +506,9 @@ void ufshcd_print_trs(struct ufs_hba *hba, unsigned
> long bitmap, bool pr_prdt)
>                 lrbp = &hba->lrb[tag];
> 
>                 dev_err(hba->dev, "UPIU[%d] - issue time %lld us\n",
> -                               tag, ktime_to_us(lrbp->issue_time_stamp));
> +                               tag, lrbp->issue_time_stamp_local_clock
> + / 1000);
>                 dev_err(hba->dev, "UPIU[%d] - complete time %lld us\n",
> -                               tag, ktime_to_us(lrbp->compl_time_stamp));
> +                               tag, lrbp->compl_time_stamp_local_clock
> + / 1000);
>                 dev_err(hba->dev,
>                         "UPIU[%d] - Transfer Request Descriptor phys@0x%llx\n",
>                         tag, (u64)lrbp->utrd_dma_addr); @@ -569,10 +570,10 @@ static
> void ufshcd_print_host_state(struct ufs_hba *hba)
>         dev_err(hba->dev, "Clk gate=%d\n", hba->clk_gating.state);
>         dev_err(hba->dev,
>                 "last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt=%d\n",
> -               ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
> +               hba->ufs_stats.last_hibern8_exit_tstamp / 1000,
>                 hba->ufs_stats.hibern8_exit_cnt);
>         dev_err(hba->dev, "last intr at %lld us, last intr status=0x%x\n",
> -               ktime_to_us(hba->ufs_stats.last_intr_ts),
> +               hba->ufs_stats.last_intr_ts / 1000,
>                 hba->ufs_stats.last_intr_status);
>         dev_err(hba->dev, "error handling flags=0x%x, req. abort count=%d\n",
>                 hba->eh_flags, hba->req_abort_count); @@ -2142,7 +2143,9 @@ void
> ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
>         unsigned long flags;
> 
>         lrbp->issue_time_stamp = ktime_get();
> +       lrbp->issue_time_stamp_local_clock = local_clock();
>         lrbp->compl_time_stamp = ktime_set(0, 0);
> +       lrbp->compl_time_stamp_local_clock = 0;
>         ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
>         ufshcd_clk_scaling_start_busy(hba);
>         if (unlikely(ufshcd_should_inform_monitor(hba, lrbp))) @@ -4199,7 +4202,7
> @@ int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
>         } else {
>                 ufshcd_vops_hibern8_notify(hba, UIC_CMD_DME_HIBER_EXIT,
>                                                                 POST_CHANGE);
> -               hba->ufs_stats.last_hibern8_exit_tstamp = ktime_get();
> +               hba->ufs_stats.last_hibern8_exit_tstamp = local_clock();
>                 hba->ufs_stats.hibern8_exit_cnt++;
>         }
> 
> @@ -4696,7 +4699,7 @@ void ufshcd_update_evt_hist(struct ufs_hba *hba,
> u32 id, u32 val)
> 
>         e = &hba->ufs_stats.event[id];
>         e->val[e->pos] = val;
> -       e->tstamp[e->pos] = ktime_get();
> +       e->tstamp[e->pos] = local_clock();
>         e->cnt += 1;
>         e->pos = (e->pos + 1) % UFS_EVENT_HIST_LENGTH;
> 
> @@ -5329,6 +5332,7 @@ static void __ufshcd_transfer_req_compl(struct
> ufs_hba *hba,
>         for_each_set_bit(index, &completed_reqs, hba->nutrs) {
>                 lrbp = &hba->lrb[index];
>                 lrbp->compl_time_stamp = ktime_get();
> +               lrbp->compl_time_stamp_local_clock = local_clock();
>                 cmd = lrbp->cmd;
>                 if (cmd) {
>                         if (unlikely(ufshcd_should_inform_monitor(hba, lrbp))) @@ -6617,7
> +6621,7 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
> 
>         intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
>         hba->ufs_stats.last_intr_status = intr_status;
> -       hba->ufs_stats.last_intr_ts = ktime_get();
> +       hba->ufs_stats.last_intr_ts = local_clock();
> 
>         /*
>          * There could be max of hba->nutrs reqs in flight and in worst case diff --git
> a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h index
> a92271421718e..2de73196bb779 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -160,8 +160,10 @@ struct ufs_pm_lvl_states {
>   * @task_tag: Task tag of the command
>   * @lun: LUN of the command
>   * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
> - * @issue_time_stamp: time stamp for debug purposes
> - * @compl_time_stamp: time stamp for statistics
> + * @issue_time_stamp: time stamp for debug purposes (CLOCK_MONOTONIC)
> + * @issue_time_stamp_local_clock: time stamp for debug purposes
> + (local_clock)
> + * @compl_time_stamp: time stamp for statistics (CLOCK_MONOTONIC)
> + * @compl_time_stamp_local_clock: time stamp for debug purposes
> + (local_clock)
>   * @crypto_key_slot: the key slot to use for inline crypto (-1 if none)
>   * @data_unit_num: the data unit number for the first block for inline crypto
>   * @req_abort_skip: skip request abort task flag @@ -185,7 +187,9 @@ struct
> ufshcd_lrb {
>         u8 lun; /* UPIU LUN id field is only 8-bit wide */
>         bool intr_cmd;
>         ktime_t issue_time_stamp;
> +       u64 issue_time_stamp_local_clock;
>         ktime_t compl_time_stamp;
> +       u64 compl_time_stamp_local_clock;
>  #ifdef CONFIG_SCSI_UFS_CRYPTO
>         int crypto_key_slot;
>         u64 data_unit_num;
> @@ -430,7 +434,7 @@ struct ufs_clk_scaling {  struct ufs_event_hist {
>         int pos;
>         u32 val[UFS_EVENT_HIST_LENGTH];
> -       ktime_t tstamp[UFS_EVENT_HIST_LENGTH];
> +       u64 tstamp[UFS_EVENT_HIST_LENGTH];
>         unsigned long long cnt;
>  };
> 
> @@ -446,10 +450,10 @@ struct ufs_event_hist {
>   */
>  struct ufs_stats {
>         u32 last_intr_status;
> -       ktime_t last_intr_ts;
> +       u64 last_intr_ts;
> 
>         u32 hibern8_exit_cnt;
> -       ktime_t last_hibern8_exit_tstamp;
> +       u64 last_hibern8_exit_tstamp;
>         struct ufs_event_hist event[UFS_EVT_CNT];  };
> 
> --
> 2.31.0
diff mbox series

Patch

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index ce86d1b790c05..e61dafb93986f 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -21,6 +21,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
+#include <linux/sched/clock.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_driver.h>
@@ -460,7 +461,7 @@  static void ufshcd_print_evt(struct ufs_hba *hba, u32 id,
 		if (e->tstamp[p] == 0)
 			continue;
 		dev_err(hba->dev, "%s[%d] = 0x%x at %lld us\n", err_name, p,
-			e->val[p], ktime_to_us(e->tstamp[p]));
+			e->val[p], e->tstamp[p] / 1000);
 		found = true;
 	}
 
@@ -505,9 +506,9 @@  void ufshcd_print_trs(struct ufs_hba *hba, unsigned long bitmap, bool pr_prdt)
 		lrbp = &hba->lrb[tag];
 
 		dev_err(hba->dev, "UPIU[%d] - issue time %lld us\n",
-				tag, ktime_to_us(lrbp->issue_time_stamp));
+				tag, lrbp->issue_time_stamp_local_clock / 1000);
 		dev_err(hba->dev, "UPIU[%d] - complete time %lld us\n",
-				tag, ktime_to_us(lrbp->compl_time_stamp));
+				tag, lrbp->compl_time_stamp_local_clock / 1000);
 		dev_err(hba->dev,
 			"UPIU[%d] - Transfer Request Descriptor phys@0x%llx\n",
 			tag, (u64)lrbp->utrd_dma_addr);
@@ -569,10 +570,10 @@  static void ufshcd_print_host_state(struct ufs_hba *hba)
 	dev_err(hba->dev, "Clk gate=%d\n", hba->clk_gating.state);
 	dev_err(hba->dev,
 		"last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt=%d\n",
-		ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
+		hba->ufs_stats.last_hibern8_exit_tstamp / 1000,
 		hba->ufs_stats.hibern8_exit_cnt);
 	dev_err(hba->dev, "last intr at %lld us, last intr status=0x%x\n",
-		ktime_to_us(hba->ufs_stats.last_intr_ts),
+		hba->ufs_stats.last_intr_ts / 1000,
 		hba->ufs_stats.last_intr_status);
 	dev_err(hba->dev, "error handling flags=0x%x, req. abort count=%d\n",
 		hba->eh_flags, hba->req_abort_count);
@@ -2142,7 +2143,9 @@  void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
 	unsigned long flags;
 
 	lrbp->issue_time_stamp = ktime_get();
+	lrbp->issue_time_stamp_local_clock = local_clock();
 	lrbp->compl_time_stamp = ktime_set(0, 0);
+	lrbp->compl_time_stamp_local_clock = 0;
 	ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
 	ufshcd_clk_scaling_start_busy(hba);
 	if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
@@ -4199,7 +4202,7 @@  int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
 	} else {
 		ufshcd_vops_hibern8_notify(hba, UIC_CMD_DME_HIBER_EXIT,
 								POST_CHANGE);
-		hba->ufs_stats.last_hibern8_exit_tstamp = ktime_get();
+		hba->ufs_stats.last_hibern8_exit_tstamp = local_clock();
 		hba->ufs_stats.hibern8_exit_cnt++;
 	}
 
@@ -4696,7 +4699,7 @@  void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val)
 
 	e = &hba->ufs_stats.event[id];
 	e->val[e->pos] = val;
-	e->tstamp[e->pos] = ktime_get();
+	e->tstamp[e->pos] = local_clock();
 	e->cnt += 1;
 	e->pos = (e->pos + 1) % UFS_EVENT_HIST_LENGTH;
 
@@ -5329,6 +5332,7 @@  static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
 	for_each_set_bit(index, &completed_reqs, hba->nutrs) {
 		lrbp = &hba->lrb[index];
 		lrbp->compl_time_stamp = ktime_get();
+		lrbp->compl_time_stamp_local_clock = local_clock();
 		cmd = lrbp->cmd;
 		if (cmd) {
 			if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
@@ -6617,7 +6621,7 @@  static irqreturn_t ufshcd_intr(int irq, void *__hba)
 
 	intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
 	hba->ufs_stats.last_intr_status = intr_status;
-	hba->ufs_stats.last_intr_ts = ktime_get();
+	hba->ufs_stats.last_intr_ts = local_clock();
 
 	/*
 	 * There could be max of hba->nutrs reqs in flight and in worst case
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index a92271421718e..2de73196bb779 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -160,8 +160,10 @@  struct ufs_pm_lvl_states {
  * @task_tag: Task tag of the command
  * @lun: LUN of the command
  * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
- * @issue_time_stamp: time stamp for debug purposes
- * @compl_time_stamp: time stamp for statistics
+ * @issue_time_stamp: time stamp for debug purposes (CLOCK_MONOTONIC)
+ * @issue_time_stamp_local_clock: time stamp for debug purposes (local_clock)
+ * @compl_time_stamp: time stamp for statistics (CLOCK_MONOTONIC)
+ * @compl_time_stamp_local_clock: time stamp for debug purposes (local_clock)
  * @crypto_key_slot: the key slot to use for inline crypto (-1 if none)
  * @data_unit_num: the data unit number for the first block for inline crypto
  * @req_abort_skip: skip request abort task flag
@@ -185,7 +187,9 @@  struct ufshcd_lrb {
 	u8 lun; /* UPIU LUN id field is only 8-bit wide */
 	bool intr_cmd;
 	ktime_t issue_time_stamp;
+	u64 issue_time_stamp_local_clock;
 	ktime_t compl_time_stamp;
+	u64 compl_time_stamp_local_clock;
 #ifdef CONFIG_SCSI_UFS_CRYPTO
 	int crypto_key_slot;
 	u64 data_unit_num;
@@ -430,7 +434,7 @@  struct ufs_clk_scaling {
 struct ufs_event_hist {
 	int pos;
 	u32 val[UFS_EVENT_HIST_LENGTH];
-	ktime_t tstamp[UFS_EVENT_HIST_LENGTH];
+	u64 tstamp[UFS_EVENT_HIST_LENGTH];
 	unsigned long long cnt;
 };
 
@@ -446,10 +450,10 @@  struct ufs_event_hist {
  */
 struct ufs_stats {
 	u32 last_intr_status;
-	ktime_t last_intr_ts;
+	u64 last_intr_ts;
 
 	u32 hibern8_exit_cnt;
-	ktime_t last_hibern8_exit_tstamp;
+	u64 last_hibern8_exit_tstamp;
 	struct ufs_event_hist event[UFS_EVT_CNT];
 };