Re: [PATCH v4 16/17] scsi: ufs: Optimize the command queueing code

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Mon 13 Dec 22:57 CST 2021, Bart Van Assche wrote:

> On 12/13/21 20:04, Bjorn Andersson wrote:
> > Can you please help me understand what I'm missing? Or how you tested
> > this?
> 
> Hi Bjorn,
> 
> Unfortunately I don't have access to a test setup with a Qualcomm chipset.
> Please help verifying whether this patch is sufficient as a fix (see also https://lore.kernel.org/linux-scsi/101fa5ba-6d74-6c51-aaa2-e6c6d98f6bc7@acm.org/):

Thanks for the proposed fix!

> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 6d692aae67ce..244eddf0caf8 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1084,7 +1084,9 @@ static u32 ufshcd_pending_cmds(struct ufs_hba *hba)
>   	struct scsi_device *sdev;
>   	u32 pending = 0;
> 
> -	shost_for_each_device(sdev, hba->host)
> +	lockdep_assert_held(hba->host->host_lock);
> +
> +	__shost_for_each_device(sdev, hba->host)

I can confirm that this resolves the issue I saw and allow me to boot my
boards again. Can you please spin this in a patch?

Feel free to add my:

Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Thanks,
Bjorn

>   		pending += sbitmap_weight(&sdev->budget_map);
> 
>   	return pending;
> 
> Thanks,
> 
> Bart.