LinuxLists.cc - [PATCH v2] ufs: core: ufshcd: use local

2022-08-01 04:51:00

Subject: [PATCH v2] ufs: core: ufshcd: use local_clock() for debugging timestamps

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 patch 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 <[email protected]>

---

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

drivers/ufs/core/ufshcd.c | 19 +++++++++++--------
include/ufs/ufshcd.h | 14 +++++++++-----
2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index ce86d1b790c05..86875a626ea77 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -460,7 +460,7 @@ 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 +505,9 @@ 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 +569,10 @@ 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 +2142,9 @@ 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 +4201,7 @@ 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 +4698,7 @@ 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 +5331,7 @@ 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 +6620,7 @@ 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

2022-08-01 06:03:36

by Stanley Jhu

[permalink] [raw]

Subject: Re: [PATCH v2] ufs: core: ufshcd: use local_clock() for debugging timestamps

Hi,

On Mon, Aug 1, 2022 at 12:30 PM Daniil Lunev <[email protected]> wrote:
>
> 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 patch 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 <[email protected]>
>
I am not sure if it is better to keep only one kind of timestamp in
the UFS driver.

Either way, it looks good to me.

Acked-by: Stanley Chu <[email protected]>

2022-08-01 10:41:26

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH v2] ufs: core: ufshcd: use local_clock() for debugging timestamps

2022-08-02 00:34:11

by kernel test robot

[permalink] [raw]

Subject: Re: [PATCH v2] ufs: core: ufshcd: use local_clock() for debugging timestamps

Hi Daniil,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on jejb-scsi/for-next]
[also build test ERROR on mkp-scsi/for-next linus/master v5.19 next-20220728]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Daniil-Lunev/ufs-core-ufshcd-use-local_clock-for-debugging-timestamps/20220801-123157
base: https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next
config: x86_64-randconfig-a001-20220801 (https://download.01.org/0day-ci/archive/20220802/[email protected]/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 52cd00cabf479aa7eb6dbb063b7ba41ea57bce9e)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/45a46347597e5c368c27a9fe01e400af675eb5e9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Daniil-Lunev/ufs-core-ufshcd-use-local_clock-for-debugging-timestamps/20220801-123157
git checkout 45a46347597e5c368c27a9fe01e400af675eb5e9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/ufs/ kernel/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>

All errors (new ones prefixed by >>):

>> drivers/ufs/core/ufshcd.c:2143:39: error: call to undeclared function 'local_clock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
lrbp->issue_time_stamp_local_clock = local_clock();
^
drivers/ufs/core/ufshcd.c:4227:45: error: call to undeclared function 'local_clock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
hba->ufs_stats.last_hibern8_exit_tstamp = local_clock();
^
drivers/ufs/core/ufshcd.c:4729:22: error: call to undeclared function 'local_clock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
e->tstamp[e->pos] = local_clock();
^
drivers/ufs/core/ufshcd.c:5362:40: error: call to undeclared function 'local_clock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
lrbp->compl_time_stamp_local_clock = local_clock();
^
drivers/ufs/core/ufshcd.c:6651:32: error: call to undeclared function 'local_clock'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
hba->ufs_stats.last_intr_ts = local_clock();
^
drivers/ufs/core/ufshcd.c:9553:44: warning: shift count >= width of type [-Wshift-count-overflow]
if (!dma_set_mask_and_coherent(hba->dev, DMA_BIT_MASK(64)))
^~~~~~~~~~~~~~~~
include/linux/dma-mapping.h:76:54: note: expanded from macro 'DMA_BIT_MASK'
#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
^ ~~~
1 warning and 5 errors generated.

vim +/local_clock +2143 drivers/ufs/core/ufshcd.c

2130
2131 /**
2132 * ufshcd_send_command - Send SCSI or device management commands
2133 * @hba: per adapter instance
2134 * @task_tag: Task tag of the command
2135 */
2136 static inline
2137 void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
2138 {
2139 struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
2140 unsigned long flags;
2141
2142 lrbp->issue_time_stamp = ktime_get();
> 2143 lrbp->issue_time_stamp_local_clock = local_clock();
2144 lrbp->compl_time_stamp = ktime_set(0, 0);
2145 lrbp->compl_time_stamp_local_clock = 0;
2146 ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
2147 ufshcd_clk_scaling_start_busy(hba);
2148 if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
2149 ufshcd_start_monitor(hba, lrbp);
2150
2151 spin_lock_irqsave(&hba->outstanding_lock, flags);
2152 if (hba->vops && hba->vops->setup_xfer_req)
2153 hba->vops->setup_xfer_req(hba, task_tag, !!lrbp->cmd);
2154 __set_bit(task_tag, &hba->outstanding_reqs);
2155 ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
2156 spin_unlock_irqrestore(&hba->outstanding_lock, flags);
2157 }
2158

--
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https://01.org/lkp