[PATCH v1] scsi: ufs: remove clk_scaling_lock when clkscaling isn't supported.

Kiwoong Kim
2022-02-05T07:41:35Z

clk_scaling_lock is to prevent from running clkscaling related operations
with others which might be affected by the operations concurrently.
I think it looks hardware specific.
If the feature isn't supported, I think there is no reasonto prevent from
running other functions, such as ufshcd_queuecommand and
ufshcd_exec_dev_cmd, concurrently.

So I add a condition at some points protecting with clk_scaling_lock.

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
drivers/scsi/ufs/ufshcd.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 460d2b4..8471c90 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2980,7 +2980,8 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
/* Protects use of hba->reserved_slot. */
lockdep_assert_held(&hba->dev_cmd.lock);

- down_read(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ down_read(&hba->clk_scaling_lock);

lrbp = &hba->lrb[tag];
WARN_ON(lrbp->cmd);
@@ -2998,7 +2999,8 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,
(struct utp_upiu_req *)lrbp->ucd_rsp_ptr);

out:
- up_read(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ up_read(&hba->clk_scaling_lock);
return err;
}

@@ -6014,7 +6016,8 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
if (ufshcd_is_clkscaling_supported(hba) &&
hba->clk_scaling.is_enabled)
ufshcd_suspend_clkscaling(hba);
- ufshcd_clk_scaling_allow(hba, false);
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_allow(hba, false);
}
ufshcd_scsi_block_requests(hba);
/* Drain ufshcd_queuecommand() */
@@ -6247,7 +6250,8 @@ static void ufshcd_err_handler(struct work_struct *work)
* Hold the scaling lock just in case dev cmds
* are sent via bsg and/or sysfs.
*/
- down_write(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ down_write(&hba->clk_scaling_lock);
hba->force_pmc = true;
pmc_err = ufshcd_config_pwr_mode(hba, &(hba->pwr_info));
if (pmc_err) {
@@ -6257,7 +6261,8 @@ static void ufshcd_err_handler(struct work_struct *work)
}
hba->force_pmc = false;
ufshcd_print_pwr_info(hba);
- up_write(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ up_write(&hba->clk_scaling_lock);
spin_lock_irqsave(hba->host->host_lock, flags);
}

@@ -6753,7 +6758,8 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
/* Protects use of hba->reserved_slot. */
lockdep_assert_held(&hba->dev_cmd.lock);

- down_read(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ down_read(&hba->clk_scaling_lock);

lrbp = &hba->lrb[tag];
WARN_ON(lrbp->cmd);
@@ -6822,7 +6828,8 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,
ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR : UFS_QUERY_COMP,
(struct utp_upiu_req *)lrbp->ucd_rsp_ptr);

- up_read(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ up_read(&hba->clk_scaling_lock);
return err;
}

--
2.7.4