Re: [PATCH v1] scsi: ufs: remove clk_scaling_lock when clkscaling isn't supported.

[Bean Huo]

On Sat, 2022-02-12 at 13:44 +0900, Kiwoong Kim wrote:
> > The error handler really should have exclusive access.  One of the
> > places
> > you change does explain that:
> > 
> >  		 * Hold the scaling lock just in case dev cmds
> >  		 * are sent via bsg and/or sysfs.
> >  		 */
> > -		down_write(&hba->clk_scaling_lock);
> > +		if (ufshcd_is_clkscaling_supported(hba))
> > +			down_write(&hba->clk_scaling_lock); 
> 
> Yeah.., I saw the comment but didn't get why.
> 
> Is there anyone who knows why it's necessary for all SoCs?
> At lease, I know there is no reason to forbid concurrent executions
> of dev cmd and power mode change.
> 
> If there's nothing, how about adding a quick to ignore it?
> 
> Thanks.
> Kiwoong Kim
> 

The name of clk_scaling_lock has explained everything, for the platform
which doesn't support load-based clk scaling, doesn't need to hold this
lock.

Acked-by: Bean Huo <beanhuo@xxxxxxxxxx>