[PATCH v2] scsi: ufs: qcom: Re-fix for error handling

[PATCH v2] scsi: ufs: qcom: Re-fix for error handling

[Chanwoo Lee]

From: ChanWoo Lee <cw9316.lee@samsung.com>

I modified the code to handle errors.

The error handling code has been changed from the patch below.
-'commit 031312dbc695 ("scsi: ufs: ufs-qcom: Remove unnecessary goto statements")'

This is the case I checked.
* ufs_qcom_clk_scale_notify -> 'ufs_qcom_clk_scale_up_/down_pre_change' error -> return 0;

It is unknown whether the above commit was intended to change error handling.
However, if it is not an intended fix, a patch may be needed.

Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
---
v1->v2: Remove things already in progress
 1) ufs_qcom_host_reset -> 'reset_control_deassert' error -> return 0;
   -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-8-manivannan.sadhasivam@linaro.org/#t
 2) ufs_qcom_init_lane_clks -> 'ufs_qcom_host_clk_get(tx_lane1_sync_clk)' error -> return 0;
   -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-2-manivannan.sadhasivam@linaro.org/
---
---
 drivers/ufs/host/ufs-qcom.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 96cb8b5b4e66..17e24270477d 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -1516,9 +1516,11 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
 			err = ufs_qcom_clk_scale_up_pre_change(hba);
 		else
 			err = ufs_qcom_clk_scale_down_pre_change(hba);
-		if (err)
-			ufshcd_uic_hibern8_exit(hba);
 
+		if (err) {
+			ufshcd_uic_hibern8_exit(hba);
+			return err;
+		}
 	} else {
 		if (scale_up)
 			err = ufs_qcom_clk_scale_up_post_change(hba);
-- 
2.29.0

Re: [PATCH v2] scsi: ufs: qcom: Re-fix for error handling

[Manivannan Sadhasivam]

On Thu, Dec 14, 2023 at 11:14:01AM +0900, Chanwoo Lee wrote:
> From: ChanWoo Lee <cw9316.lee@samsung.com>
> 
> I modified the code to handle errors.
> 
> The error handling code has been changed from the patch below.
> -'commit 031312dbc695 ("scsi: ufs: ufs-qcom: Remove unnecessary goto statements")'
> 
> This is the case I checked.
> * ufs_qcom_clk_scale_notify -> 'ufs_qcom_clk_scale_up_/down_pre_change' error -> return 0;
> 
> It is unknown whether the above commit was intended to change error handling.
> However, if it is not an intended fix, a patch may be needed.
> 

Fixes: 031312dbc695 ("scsi: ufs: ufs-qcom: Remove unnecessary goto statements")

> Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks for spotting and fixing the issue! This is one of the reasons why the
error path should directly return instead of slipping.

- Mani

> Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
> ---
> v1->v2: Remove things already in progress
>  1) ufs_qcom_host_reset -> 'reset_control_deassert' error -> return 0;
>    -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-8-manivannan.sadhasivam@linaro.org/#t
>  2) ufs_qcom_init_lane_clks -> 'ufs_qcom_host_clk_get(tx_lane1_sync_clk)' error -> return 0;
>    -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-2-manivannan.sadhasivam@linaro.org/
> ---
> ---
>  drivers/ufs/host/ufs-qcom.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> index 96cb8b5b4e66..17e24270477d 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -1516,9 +1516,11 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
>  			err = ufs_qcom_clk_scale_up_pre_change(hba);
>  		else
>  			err = ufs_qcom_clk_scale_down_pre_change(hba);
> -		if (err)
> -			ufshcd_uic_hibern8_exit(hba);
>  
> +		if (err) {
> +			ufshcd_uic_hibern8_exit(hba);
> +			return err;
> +		}
>  	} else {
>  		if (scale_up)
>  			err = ufs_qcom_clk_scale_up_post_change(hba);
> -- 
> 2.29.0
> 
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v2] scsi: ufs: qcom: Re-fix for error handling

[Andrew Halaney]

On Thu, Dec 14, 2023 at 11:14:01AM +0900, Chanwoo Lee wrote:
> From: ChanWoo Lee <cw9316.lee@samsung.com>
> 
> I modified the code to handle errors.
> 
> The error handling code has been changed from the patch below.
> -'commit 031312dbc695 ("scsi: ufs: ufs-qcom: Remove unnecessary goto statements")'
> 
> This is the case I checked.
> * ufs_qcom_clk_scale_notify -> 'ufs_qcom_clk_scale_up_/down_pre_change' error -> return 0;
> 
> It is unknown whether the above commit was intended to change error handling.
> However, if it is not an intended fix, a patch may be needed.

Can you be a bit specific about what you fixed here in the commit?
Both the subject and the description is vague and sounds like you're
still unsure if this change is a good idea. The review on the prior
patch and this one is indicating that this change is necessary and a
fix, so let's be more confident in the description for future readers.

Write as you please, but something like:

    scsi: ufs: qcom: Return ufs_qcom_clk_scale_*() errors in ufs_qcom_clk_scale_notify()

    In commit 031312dbc695 ("scsi: ufs: ufs-qcom: Remove unnecessary goto statements")
    the error handling was accidentally changed, resulting in the error of
    ufs_qcom_clk_scale_*() calls not being returned.

    Let's make sure those errors are properly returned.

> 
> Signed-off-by: ChanWoo Lee <cw9316.lee@samsung.com>

This deserves a Fixes: tag (I see Mani mentioned that)

> Reviewed-by: Andrew Halaney <ahalaney@redhat.com>

I did not provide a Reviewed-by tag in v1, this is not accurate:

    https://lore.kernel.org/linux-arm-msm/m5wjp3yb3qpheyzgipekeagycboifqdpw54nquzqsftufap3yc@kxjwi4y63adj/

Outside of that this looks good, thanks!

> ---
> v1->v2: Remove things already in progress
>  1) ufs_qcom_host_reset -> 'reset_control_deassert' error -> return 0;
>    -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-8-manivannan.sadhasivam@linaro.org/#t
>  2) ufs_qcom_init_lane_clks -> 'ufs_qcom_host_clk_get(tx_lane1_sync_clk)' error -> return 0;
>    -> https://lore.kernel.org/linux-arm-msm/20231208065902.11006-2-manivannan.sadhasivam@linaro.org/
> ---
> ---
>  drivers/ufs/host/ufs-qcom.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
> index 96cb8b5b4e66..17e24270477d 100644
> --- a/drivers/ufs/host/ufs-qcom.c
> +++ b/drivers/ufs/host/ufs-qcom.c
> @@ -1516,9 +1516,11 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
>  			err = ufs_qcom_clk_scale_up_pre_change(hba);
>  		else
>  			err = ufs_qcom_clk_scale_down_pre_change(hba);
> -		if (err)
> -			ufshcd_uic_hibern8_exit(hba);
>  
> +		if (err) {
> +			ufshcd_uic_hibern8_exit(hba);
> +			return err;
> +		}
>  	} else {
>  		if (scale_up)
>  			err = ufs_qcom_clk_scale_up_post_change(hba);
> -- 
> 2.29.0
>