RE: [PATCH v2 1/2] scsi: ufs: core: Introduce a new clock_gating lock

From: Avri Altman
Date: Tue Oct 29 2024 - 14:39:21 EST


> On 10/29/24 3:29 AM, Avri Altman wrote:
> > + scoped_guard(spinlock_irqsave, &hba->clk_gating.lock) {
> > + /*
> > + * In case you are here to cancel this work the gating state
> > + * would be marked as REQ_CLKS_ON. In this case save time by
> > + * skipping the gating work and exit after changing the clock
> > + * state to CLKS_ON.
> > + */
> > + if (hba->clk_gating.is_suspended || (hba->clk_gating.state !=
> REQ_CLKS_OFF)) {
> > + hba->clk_gating.state = CLKS_ON;
> > + trace_ufshcd_clk_gating(dev_name(hba->dev), hba-
> >clk_gating.state);
> > + return;
> > + }
> > + if (ufshcd_is_ufs_dev_busy(hba) || hba->ufshcd_state !=
> UFSHCD_STATE_OPERATIONAL)
> > + return;
> > }
>
> Please remove the superfluous parentheses from around the REQ_CLKS_OFF
> test
OK.
But this is a format change while making functional change.

> and do not exceed the 80 column limit. git clang-format HEAD^ can help
> with restricting code to the 80 column limit.
Isn't the 80 characters restriction was changed long ago to 100 characters?
I always use strict checkpatch and doesn't get any warning about this.

>
> > @@ -2072,18 +2055,18 @@ static ssize_t
> > ufshcd_clkgate_enable_store(struct device *dev,
> >
> > value = !!value;
> >
> > - spin_lock_irqsave(hba->host->host_lock, flags);
> > - if (value == hba->clk_gating.is_enabled)
> > - goto out;
> > + scoped_guard(spinlock_irqsave, &hba->clk_gating.lock) {
> > + if (value == hba->clk_gating.is_enabled)
> > + goto out;
> >
> > - if (value)
> > - __ufshcd_release(hba);
> > - else
> > - hba->clk_gating.active_reqs++;
> > + if (value)
> > + __ufshcd_release(hba);
> > + else
> > + hba->clk_gating.active_reqs++;
> >
> > - hba->clk_gating.is_enabled = value;
> > + hba->clk_gating.is_enabled = value;
> > + }
> > out:
> > - spin_unlock_irqrestore(hba->host->host_lock, flags);
> > return count;
> > }
>
> Please use guard() instead of scoped_guard() and remove the "out:"
> label.
Done.

>
> > @@ -9173,11 +9157,10 @@ static int ufshcd_setup_clocks(struct ufs_hba
> *hba, bool on)
> > clk_disable_unprepare(clki->clk);
> > }
> > } else if (!ret && on) {
> > - spin_lock_irqsave(hba->host->host_lock, flags);
> > - hba->clk_gating.state = CLKS_ON;
> > + scoped_guard(spinlock_irqsave, &hba->clk_gating.lock)
> > + hba->clk_gating.state = CLKS_ON;
> > trace_ufshcd_clk_gating(dev_name(hba->dev),
> > hba->clk_gating.state);
> > - spin_unlock_irqrestore(hba->host->host_lock, flags);
> > }
>
> The above change moves the trace_ufshcd_clk_gating() call from inside the
> region protected by the host lock to outside the region protected by
> clk_gating.lock. If this is intentional, shouldn't this be mentioned in the patch
> description?
Yes. Intentional.
Done.

Thanks,
Avri

>
> Thanks,
>
> Bart.