Re: [PATCH v6 06/10] scsi: ufs: ufs-qcom: Set initial PHY gear to max HS gear for HW ver 4 and newer

From: Can Guo <quic_cang@quicinc.com>
To: Manivannan Sadhasivam <mani@kernel.org>
Cc: <bvanassche@acm.org>, <adrian.hunter@intel.com>,
	<cmd4@qualcomm.com>, <beanhuo@micron.com>, <avri.altman@wdc.com>,
	<junwoo80.lee@samsung.com>, <martin.petersen@oracle.com>,
	<linux-scsi@vger.kernel.org>, <linux-arm-msm@vger.kernel.org>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@linaro.org>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 06/10] scsi: ufs: ufs-qcom: Set initial PHY gear to max HS gear for HW ver 4 and newer
Date: Thu, 30 Nov 2023 15:49:03 +0800	[thread overview]
Message-ID: <22a49deb-001d-4fa2-83e1-0fe6c7fe2a2e@quicinc.com> (raw)
In-Reply-To: <20231130064757.GF3043@thinkpad>

On 11/30/2023 2:47 PM, Manivannan Sadhasivam wrote:
> On Wed, Nov 29, 2023 at 12:28:31AM -0800, Can Guo wrote:
>> Since HW ver 4, max HS gear can be get from UFS host controller's register,
>> use the max HS gear as the initial PHY gear instead of UFS_HS_G2, so that
>> we don't need to update the hard code for newer targets in future.
>>
>> Signed-off-by: Can Guo <quic_cang@quicinc.com>
> 
> One comment below. With that addressed,
> 
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
>> ---
>>   drivers/ufs/host/ufs-qcom.c | 21 +++++++++++++++------
>>   1 file changed, 15 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
>> index aca6199..30f4ca6 100644
>> --- a/drivers/ufs/host/ufs-qcom.c
>> +++ b/drivers/ufs/host/ufs-qcom.c
>> @@ -1060,6 +1060,20 @@ static void ufs_qcom_advertise_quirks(struct ufs_hba *hba)
>>   		hba->quirks |= UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
>>   }
>>   
>> +static void ufs_qcom_set_phy_gear(struct ufs_qcom_host *host)
>> +{
>> +	struct ufs_host_params *host_params = &host->host_params;
>> +
>> +	host->phy_gear = host_params->hs_tx_gear;
>> +
>> +	/*
>> +	 * Power up the PHY using the minimum supported gear (UFS_HS_G2).
>> +	 * Switching to max gear will be performed during reinit if supported.
> 
> As I mentioned in v5, you need to reword this comment to make it clear we are
> setting G2 only for platforms < v4. Something like below:
> 
> "For controllers whose major version is < 4, power up the PHY using minimum
> supported gear (UFS_HS_G2). Switching to max gear will be performed during
> reinit if supported. For newer controllers (>= 4), PHY will be powered up using
> max supported gear."

Sorry that I missed this one, will add in next version.

Thanks,
Can Guo.

> 
> - Mani
> 
>> +	 */
>> +	if (host->hw_ver.major < 0x4)
>> +		host->phy_gear = UFS_HS_G2;
>> +}
>> +
>>   static void ufs_qcom_set_host_params(struct ufs_hba *hba)
>>   {
>>   	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> @@ -1296,6 +1310,7 @@ static int ufs_qcom_init(struct ufs_hba *hba)
>>   	ufs_qcom_set_caps(hba);
>>   	ufs_qcom_advertise_quirks(hba);
>>   	ufs_qcom_set_host_params(hba);
>> +	ufs_qcom_set_phy_gear(host);
>>   
>>   	err = ufs_qcom_ice_init(host);
>>   	if (err)
>> @@ -1313,12 +1328,6 @@ static int ufs_qcom_init(struct ufs_hba *hba)
>>   		dev_warn(dev, "%s: failed to configure the testbus %d\n",
>>   				__func__, err);
>>   
>> -	/*
>> -	 * Power up the PHY using the minimum supported gear (UFS_HS_G2).
>> -	 * Switching to max gear will be performed during reinit if supported.
>> -	 */
>> -	host->phy_gear = UFS_HS_G2;
>> -
>>   	return 0;
>>   
>>   out_variant_clear:
>> -- 
>> 2.7.4
>>
>>
> 