Re: [PATCH 2/2] scsi: ufs: Clean up ufshcd_exit_clk_scaling/gating()

[Can Guo]

On 2020-12-11 02:03, Bean Huo wrote:
> On Wed, 2020-12-09 at 05:35 -0800, Can Guo wrote:
> > ufshcd_hba_exit() is always called after ufshcd_exit_clk_scaling()
> > and
> > ufshcd_exit_clk_gating(), so move ufshcd_exit_clk_scaling/gating() to
> > ufshcd_hba_exit().
> >
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> >
> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> > index 12266bd..41a12d6 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -1846,11 +1846,14 @@ static void ufshcd_init_clk_scaling(struct
> > ufs_hba *hba)
> >         snprintf(wq_name, sizeof(wq_name), "ufs_clkscaling_%d",
> >                  hba->host->host_no);
> >         hba->clk_scaling.workq =
> > create_singlethread_workqueue(wq_name);
> > +
> > +       hba->clk_scaling.is_initialized = true;
> >  }
> >
> >  static void ufshcd_exit_clk_scaling(struct ufs_hba *hba)
> >  {
> > -       if (!ufshcd_is_clkscaling_supported(hba))
> > +       if (!ufshcd_is_clkscaling_supported(hba) ||
> > +           !hba->clk_scaling.is_initialized)
> >                 return;
> >
> >         if (hba->devfreq)
> > @@ -1894,12 +1897,16 @@ static void ufshcd_init_clk_gating(struct
> > ufs_hba *hba)
> >         hba->clk_gating.enable_attr.attr.mode = 0644;
> >         if (device_create_file(hba->dev, &hba-
> > >clk_gating.enable_attr))
> >                 dev_err(hba->dev, "Failed to create sysfs for
> > clkgate_enable\n");
> > +
> > +       hba->clk_gating.is_initialized = true;
> >  }
>
> you don't need these two is_initialized at all. they are only be false
> when scaling/gating is not supported??
>
> Bean

In the case of scaling/gating are supported, the flags are used in
ufshcd_exit_clk_scaling/gating() - when ufshcd_hba_exit() calls
ufshcd_exit_clk_scaling/gating(), the two funcs need to make sure
they really have something to remove, otherwise NULL pointer issues.

Can Guo.