Re: [PATCH v2 1/1] scsi: ufs: core: add device level exception support

[Bao D. Nguyen]

On 3/18/2025 2:21 PM, Bart Van Assche wrote:
> On 3/14/25 3:55 PM, Bao D. Nguyen wrote:
> > +    if (status & hba->ee_drv_mask & MASK_EE_DEV_LVL_EXCEPTION) {
> > +        hba->dev_lvl_exception_count++;
> > +        sysfs_notify(&hba->dev->kobj, NULL, 
> > "device_lvl_exception_count");
> > +    }
> This increment can race with the code in 
> device_lvl_exception_count_store() for clearing
> hba->dev_lvl_exception_count. Shouldn't the clearing code and the
> code for incrementing hba->dev_lvl_exception_count be serialized in
> some way?
Thank you for the good catch, Bart. I do need to protect this racing 
condition in the functions you mentioned. This dev_lvl_exception_count 
variable is also initialized in the ufshcd_device_lvl_exception_probe() 
function at which point the sysfs nodes have already been initialized, 
but since both the device_lvl_exception_count_store() and the 
ufshcd_device_lvl_exception_probe() write 0 to dev_lvl_exception_count, 
it should be no problem there.

I will fix it.

Thanks, Bao