Re: [PATCH] scsi: ufs: core: Fix setup_xfer_req invocation

[Can Guo <quic_cang@quicinc.com>]

Hi Bart,

On 2/21/2024 1:21 AM, Bart Van Assche wrote:
> On 2/20/24 01:08, Rohit Ner wrote:
>> Allow variant callback to setup transfers without
>> restricting the transfers to use legacy doorbell
>>
>> Signed-off-by: Rohit Ner <rohitner@google.com>
>> ---
>>   drivers/ufs/core/ufshcd.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
>> index d77b25b79ae3..91e483dd3974 100644
>> --- a/drivers/ufs/core/ufshcd.c
>> +++ b/drivers/ufs/core/ufshcd.c
>> @@ -2280,6 +2280,9 @@ void ufshcd_send_command(struct ufs_hba *hba, 
>> unsigned int task_tag,
>>           ufshcd_clk_scaling_start_busy(hba);
>>       if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
>>           ufshcd_start_monitor(hba, lrbp);
>> +    if (hba->vops && hba->vops->setup_xfer_req)
>> +        hba->vops->setup_xfer_req(hba, lrbp->task_tag,
>> +                        !!lrbp->cmd);
>>       if (is_mcq_enabled(hba)) {
>>           int utrd_size = sizeof(struct utp_transfer_req_desc);
>> @@ -2293,9 +2296,6 @@ void ufshcd_send_command(struct ufs_hba *hba, 
>> unsigned int task_tag,
>>           spin_unlock(&hwq->sq_lock);
>>       } else {
>>           spin_lock_irqsave(&hba->outstanding_lock, flags);
>> -        if (hba->vops && hba->vops->setup_xfer_req)
>> -            hba->vops->setup_xfer_req(hba, lrbp->task_tag,
>> -                          !!lrbp->cmd);
>>           __set_bit(lrbp->task_tag, &hba->outstanding_reqs);
>>           ufshcd_writel(hba, 1 << lrbp->task_tag,
>>                     REG_UTP_TRANSFER_REQ_DOOR_BELL);
> 
> UFS controllers that are compliant with the JEDEC UFSHCI specification do
> not need the .setup_xfer_req() callback so I think a better motivation is
> needed to make this change.

I am going to push some BUG fixes for Qualcomm UFSHCI MCQ engine, one of 
which would count on a vops in ufshcd_send_command(). My original plan 
was to add a new vops.mcq_setup_xfer_req() to differentiate from the 
existing one used in legacy mode. But if Rohit moves the existing 
.setup_xfer_req() up, I can use it instead of introducing the new one.

Thanks,
Can Guo.

> 
> Thanks,
> 
> Bart.