Re: [PATCH v2 4/7] scsi: ufs: ufs-qcom: Limit HS-G5 Rate-A to hosts with HW version 5

[Can Guo <quic_cang@quicinc.com>]

Hi Mani,

On 11/8/2023 1:25 PM, Manivannan Sadhasivam wrote:
> On Mon, Nov 06, 2023 at 08:46:10PM -0800, Can Guo wrote:
>> From: Can Guo <quic_cang@quicinc.com>
>>
>> Qcom UFS hosts, with HW ver 5, can only support up to HS-G5 Rate-A due to
>> HW limitations. If the HS-G5 PHY gear is used, update host_params->hs_rate
>> to Rate-A, so that the subsequent power mode changes shall stick to Rate-A.
>>
>> Signed-off-by: Can Guo <quic_cang@quicinc.com>
>> ---
>>   drivers/ufs/host/ufs-qcom.c | 18 +++++++++++++++++-
>>   1 file changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
>> index 60b35ca..55ee31d 100644
>> --- a/drivers/ufs/host/ufs-qcom.c
>> +++ b/drivers/ufs/host/ufs-qcom.c
>> @@ -442,9 +442,25 @@ static u32 ufs_qcom_get_hs_gear(struct ufs_hba *hba)
>>   static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
>>   {
>>   	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
>> +	struct ufs_host_params *host_params = &host->host_params;
>>   	struct phy *phy = host->generic_phy;
>> +	enum phy_mode mode;
>>   	int ret;
>>   
>> +	/*
>> +	 * HW ver 5 can only support up to HS-G5 Rate-A due to HW limitations.
> 
> Does this limitation apply to future targets as well or just to SM8550? If
> it's the latter, then we need to use a flag.
> 
> - ManiUFS host controller HW ver (major) 5 IPs (they may have different 
minor/step verions) can be used by many QCOM chipsets, so it applies to 
several available targets and future targets which are going to have HW 
ver 5 UFS host controller. This limitation goes away since HW ver 6.

Thanks,
Can Guo.