Re: [PATCH V6 1/6] scsi: ufs: qcom: Align mask for core_clk_1us_cycles

[Nitin Rawat <quic_nitirawa@quicinc.com>]

On 9/1/2023 8:47 PM, Bjorn Andersson wrote:
> On Fri, Sep 01, 2023 at 05:13:31PM +0530, Nitin Rawat wrote:
>> Align core_clk_1us_cycles mask for Qualcomm UFS Controller V4.0.0
> 
> "Align clk mask for ... as per hardware specification."? Are you trying
> to say "The DME_VS_CORE_CLK_CTRL register has changed in v4 of the
> Qualcomm UFS controller, introduce support for the new register layout"?
> 
> You're not aligning the code to match the hardware specification, you're
> fixing the code because the register has changed.
> 
>> onwards as per Hardware Specification.
>>

Hi Bjorn,

Yes, will update the commit text in next patchset



>> Co-developed-by: Naveen Kumar Goud Arepalli <quic_narepall@quicinc.com>
>> Signed-off-by: Naveen Kumar Goud Arepalli <quic_narepall@quicinc.com>
>> Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
>> ---
>>   drivers/ufs/host/ufs-qcom.c | 28 ++++++++++++++++++----------
>>   drivers/ufs/host/ufs-qcom.h |  5 +++--
>>   2 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
>> index f88febb23123..fe36003faaa8 100644
>> --- a/drivers/ufs/host/ufs-qcom.c
>> +++ b/drivers/ufs/host/ufs-qcom.c
>> @@ -1297,22 +1297,30 @@ static void ufs_qcom_exit(struct ufs_hba *hba)
>>   }
>>
>>   static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
>> -						       u32 clk_cycles)
>> +						       u32 cycles_in_1us)
> 
> This is a nice clarification, but changing the function prototype gives
> a sense that you changed the parameters - and that's not the case.
> 
> So if you drop this rename, you make the purpose of the patch clearer.
> 
>>   {
>> -	int err;
>> +	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>>   	u32 core_clk_ctrl_reg;
>> +	int ret;
> 
> Renaming err to ret is unrelated and only unnecessary complexity to the
> patch.
> 

ok..Would take care of this comment in next patchset.


>>
>> -	if (clk_cycles > DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK)
>> -		return -EINVAL;
>> -
>> -	err = ufshcd_dme_get(hba,
>> +	ret = ufshcd_dme_get(hba,
>>   			    UIC_ARG_MIB(DME_VS_CORE_CLK_CTRL),
>>   			    &core_clk_ctrl_reg);
>> -	if (err)
>> -		return err;
>> +	if (ret)
>> +		return ret;
>>
>> -	core_clk_ctrl_reg &= ~DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK;
>> -	core_clk_ctrl_reg |= clk_cycles;
>> +	/* Bit mask is different for UFS host controller V4.0.0 onwards */
>> +	if (host->hw_ver.major >= 4) {
>> +		if (!FIELD_FIT(CLK_1US_CYCLES_MASK_V4, cycles_in_1us))
>> +			return -ERANGE;
>> +		core_clk_ctrl_reg &= ~CLK_1US_CYCLES_MASK_V4;
>> +		core_clk_ctrl_reg |= FIELD_PREP(CLK_1US_CYCLES_MASK_V4, cycles_in_1us);
>> +	} else {
>> +		if (!FIELD_FIT(CLK_1US_CYCLES_MASK, cycles_in_1us))
>> +			return -ERANGE;
>> +		core_clk_ctrl_reg &= ~CLK_1US_CYCLES_MASK;
>> +		core_clk_ctrl_reg |= FIELD_PREP(CLK_1US_CYCLES_MASK, cycles_in_1us);
>> +	}
>>
>>   	/* Clear CORE_CLK_DIV_EN */
>>   	core_clk_ctrl_reg &= ~DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT;
>> diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
>> index d6f8e74bd538..8a9d3dbec297 100644
>> --- a/drivers/ufs/host/ufs-qcom.h
>> +++ b/drivers/ufs/host/ufs-qcom.h
>> @@ -129,8 +129,9 @@ enum {
>>   #define PA_VS_CONFIG_REG1	0x9000
>>   #define DME_VS_CORE_CLK_CTRL	0xD002
>>   /* bit and mask definitions for DME_VS_CORE_CLK_CTRL attribute */
>> -#define DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT		BIT(8)
>> -#define DME_VS_CORE_CLK_CTRL_MAX_CORE_CLK_1US_CYCLES_MASK	0xFF
>> +#define CLK_1US_CYCLES_MASK_V4				GENMASK(27, 16)
>> +#define CLK_1US_CYCLES_MASK				GENMASK(7, 0)
>> +#define DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT	BIT(8)
> 
> Hard to say without applying the patch, please double check that the
> values here have matching indentation level.
> 
> Thank you,
> Bjorn

-Yes I applied and confirmed it's proper.

Thanks,
Nitin


> 
>>
>>   static inline void
>>   ufs_qcom_get_controller_revision(struct ufs_hba *hba,
>> --
>> 2.17.1
>>