Re: [PATCH 2/2] scsi: ufs: core: Fix the code for entering hibernation

["Bao D. Nguyen" <quic_nguyenb@quicinc.com>]

On 8/23/2024 1:25 PM, Bart Van Assche wrote:

> If the UIC command completion interrupt could come late we would
> already have observed unhandled interrupt errors in device logs, isn't
> it?
> 
> Anyway, isn't this something that is easy to fix with something like the
> (untested) patch below?
> 
> 
> @@ -2559,8 +2557,7 @@ __ufshcd_send_uic_cmd(struct ufs_hba *hba, struct 
> uic_command *uic_cmd,
>           return -EIO;
>       }
> 
> -    if (completion)
> -        init_completion(&uic_cmd->done);
> +    init_completion(&uic_cmd->done);

This change may not work, Bart.
In this path ufshcd_uic_pwr_ctrl()->__ufshcd_send_uic_cmd(), the 
proposal always has a init_completion(&uic_cmd->done). However, there is 
no ufshcd_wait_for_uic_cmd() in this path. The isr will call 
ufshcd_uic_cmd_compl()->complete(&hba->active_uic_cmd->done); to signal 
the completion, but you are missing the code that waits for the 
&hba->active_uic_cmd->done signal, so it may cause stability issues.

I am going to review another of your proposal in the mail with Peter and 
get back.

Thanks, Bao