[PATCH v4 1/2] scsi: ufs: export hibern8 entry

[PATCH v4 1/2] scsi: ufs: export hibern8 entry

[Asutosh Das]

Qualcomm controllers need to be in hibern8 before scaling up
or down the clocks. Hence, export the hibern8 entry function.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 4 ++--
 drivers/scsi/ufs/ufshcd.h | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c3389c9..aaf4adf 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -243,7 +243,6 @@ static int ufshcd_probe_hba(struct ufs_hba *hba, bool async);
 static int __ufshcd_setup_clocks(struct ufs_hba *hba, bool on,
 				 bool skip_ref_clk);
 static int ufshcd_setup_clocks(struct ufs_hba *hba, bool on);
-static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
 static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba);
 static int ufshcd_host_reset_and_restore(struct ufs_hba *hba);
 static void ufshcd_resume_clkscaling(struct ufs_hba *hba);
@@ -3877,7 +3876,7 @@ static int __ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 	return ret;
 }
 
-static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
+int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 {
 	int ret = 0, retries;
 
@@ -3889,6 +3888,7 @@ static int ufshcd_uic_hibern8_enter(struct ufs_hba *hba)
 out:
 	return ret;
 }
+EXPORT_SYMBOL_GPL(ufshcd_uic_hibern8_enter);
 
 int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
 {
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 88d4202..defc12c 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -835,6 +835,7 @@ int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
 void ufshcd_parse_dev_ref_clk_freq(struct ufs_hba *hba, struct clk *refclk);
 void ufshcd_update_reg_hist(struct ufs_err_reg_hist *reg_hist,
 			    u32 reg);
+int ufshcd_uic_hibern8_enter(struct ufs_hba *hba);
 
 static inline void check_upiu_size(void)
 {
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH v4 2/2] scsi: ufs-qcom: enter and exit hibern8 during clock scaling

[Asutosh Das]

Qualcomm controller needs to be in hibern8 before scaling clocks.
This change puts the controller in hibern8 state before scaling
and brings it out after scaling of clocks.

Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufs-qcom.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 00ce8d6..3a4ed64 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1418,18 +1418,27 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
 	int err = 0;
 
 	if (status == PRE_CHANGE) {
+		err = ufshcd_uic_hibern8_enter(hba);
+		if (err)
+			return err;
 		if (scale_up)
 			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);
+
 	} else {
 		if (scale_up)
 			err = ufs_qcom_clk_scale_up_post_change(hba);
 		else
 			err = ufs_qcom_clk_scale_down_post_change(hba);
 
-		if (err || !dev_req_params)
+
+		if (err || !dev_req_params) {
+			ufshcd_uic_hibern8_exit(hba);
 			goto out;
+		}
 
 		ufs_qcom_cfg_timers(hba,
 				    dev_req_params->gear_rx,
@@ -1437,6 +1446,7 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
 				    dev_req_params->hs_rate,
 				    false);
 		ufs_qcom_update_bus_bw_vote(host);
+		err = ufshcd_uic_hibern8_exit(hba);
 	}
 
 out:
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

RE: [PATCH v4 2/2] scsi: ufs-qcom: enter and exit hibern8 during clock scaling

[Avri Altman]

Hi,

> 
> 
> Qualcomm controller needs to be in hibern8 before scaling clocks.
> This change puts the controller in hibern8 state before scaling
> and brings it out after scaling of clocks.
> 
> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>

I guess that your previous versions are pretty far back - ,
I noticed a comment by Pedro, so you might want to resend this series.

What happens if the pre-change is successful,
but you are not getting to the post change because, e.g. ufshcd_set_clk_freq failed?

Also, this piece of code is ~5 years old, so you might want to elaborate on how come hibernation is now needed.

Thanks,
Avri

Re: [PATCH v4 2/2] scsi: ufs-qcom: enter and exit hibern8 during clock scaling

[Asutosh Das (asd)]

Hi Avri,

On 5/20/2020 2:33 PM, Avri Altman wrote:
> Hi,
> 
>>
>>
>> Qualcomm controller needs to be in hibern8 before scaling clocks.
>> This change puts the controller in hibern8 state before scaling
>> and brings it out after scaling of clocks.
>>
>> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
> 
> I guess that your previous versions are pretty far back - ,
> I noticed a comment by Pedro, so you might want to resend this series.
> 
Ok.

> What happens if the pre-change is successful,
> but you are not getting to the post change because, e.g. ufshcd_set_clk_freq failed?
> 
I agree. Let me check this.

> Also, this piece of code is ~5 years old, so you might want to elaborate on how come hibernation is now needed.
> 
> Thanks,
> Avri
> 

Thanks for the review. Hibernation was needed since long actually.
I guess it was never pushed upstream.

Thanks,
-asd

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
Linux Foundation Collaborative Project

Re: [PATCH v4 2/2] scsi: ufs-qcom: enter and exit hibern8 during clock scaling

[Asutosh Das (asd)]

On 5/25/2021 12:57 AM, Lee Jones wrote:
> On Wed, 20 May 2020 at 22:59, Asutosh Das (asd) <asutoshd@codeaurora.org 
> <mailto:asutoshd@codeaurora.org>> wrote:
> 
>     Hi Avri,
> 
>     On 5/20/2020 2:33 PM, Avri Altman wrote:
>      > Hi,
>      >
>      >>
>      >>
>      >> Qualcomm controller needs to be in hibern8 before scaling clocks.
>      >> This change puts the controller in hibern8 state before scaling
>      >> and brings it out after scaling of clocks.
>      >>
>      >> Signed-off-by: Asutosh Das <asutoshd@codeaurora.org
>     <mailto:asutoshd@codeaurora.org>>
>      >
>      > I guess that your previous versions are pretty far back - ,
>      > I noticed a comment by Pedro, so you might want to resend this
>     series.
>      >
>     Ok.
> 
>      > What happens if the pre-change is successful,
>      > but you are not getting to the post change because, e.g.
>     ufshcd_set_clk_freq failed?
>      >
>     I agree. Let me check this.
> 
>      > Also, this piece of code is ~5 years old, so you might want to
>     elaborate on how come hibernation is now needed.
>      >
>      > Thanks,
>      > Avri
>      >
> 
>     Thanks for the review. Hibernation was needed since long actually.
>     I guess it was never pushed upstream.
> 
> 
> Good morning Asd,
> 
> Any luck with getting this upstream?
> 
> Looks like this was the last submission.
> 
> Did something change?  Is this no longer required?
> 
Hi Lee
This slipped away. I may not get to this soon.
I'd prefer to drop it for now and come back to it when I've some time.

Thanks,
-asd

> -- 
> Lee Jones [李琼斯]
> Linaro Services Senior Technical Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog


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Linux Foundation Collaborative Project