From: Tony Lindgren <tony@atomide.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Greg KH <gregkh@linuxfoundation.org>,
Lin Ruizhe <linruizhe@huawei.com>,
rui.zhang@intel.com, edubezval@gmail.com, j-keerthy@ti.com,
amitk@kernel.org, radhesh.fadnis@ti.com, eballetbo@gmail.com,
linux-pm@vger.kernel.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] thermal: ti-soc-thermal: Remove unused variable 'val'
Date: Wed, 21 Apr 2021 12:37:07 +0300 [thread overview]
Message-ID: <YH/yQ5Hd+30DH4p/@atomide.com> (raw)
In-Reply-To: <8e66040e-4330-d4f0-afbb-8cae62a5082e@linaro.org>
* Daniel Lezcano <daniel.lezcano@linaro.org> [210421 09:07]:
> On 21/04/2021 10:49, Greg KH wrote:
> > On Wed, Apr 21, 2021 at 04:42:56PM +0800, Lin Ruizhe wrote:
> >> The variable 'val'in function ti_bandgap_restore_ctxt is
> >> the register value of read bandgap registers. This function is to
> >> restore the context. But there is no operation on the return value
> >> of this register, so this block is redundant. Hulk robot scans this
> >> warning.This commit remove the dead code.
> >>
> >> Reported-by: Hulk Robot <hulkci@huawei.com>
> >> Fixes: b87ea759a4cc ("staging: omap-thermal: fix context restore function")
> >> Signed-off-by: Lin Ruizhe <linruizhe@huawei.com>
> >> ---
> >> v3:
> >> -Add Fixes tag and more accurate commit message in this patch.
> >> v2:
> >> -As suggest remove the whole unuesed block in fuction
> >> ti_bandgap_restore_ctxt
> >>
> >> drivers/thermal/ti-soc-thermal/ti-bandgap.c | 4 ----
> >> 1 file changed, 4 deletions(-)
> >>
> >> diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> >> index d81af89166d2..684ffb645aa9 100644
> >> --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> >> +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> >> @@ -1142,14 +1142,10 @@ static int ti_bandgap_restore_ctxt(struct ti_bandgap *bgp)
> >> for (i = 0; i < bgp->conf->sensor_count; i++) {
> >> struct temp_sensor_registers *tsr;
> >> struct temp_sensor_regval *rval;
> >> - u32 val = 0;
> >>
> >> rval = &bgp->regval[i];
> >> tsr = bgp->conf->sensors[i].registers;
> >>
> >> - if (TI_BANDGAP_HAS(bgp, COUNTER))
> >> - val = ti_bandgap_readl(bgp, tsr->bgap_counter);
> >
> > Are you sure that this hardware does not require this read to happen in
> > order for it to work properly?
>
> Yes, initially we had the same concern but we were unable to find
> anything specific in the history. The commit mentioned above removed the
> user of the 'val' code but without removing this block of code.
>
> When looking at the current code, it really looks like an oversight.
Yes so it seems.
> There is nothing in the commit's changelog referring to a need of
> reading the counter register but perhaps I'm wrong because I'm not sure
> to understand correctly the changelog.
>
> > Lots of hardware does need this, have you tested this?
I just tested this on omap3 logicpd torpedo devkit that can do off during
idle and reading /sys/class/thermal/thermal_zone0/temp works. So feel
free to add:
Reviewed-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
next prev parent reply other threads:[~2021-04-21 9:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-21 8:42 [PATCH v3] thermal: ti-soc-thermal: Remove unused variable 'val' Lin Ruizhe
2021-04-21 8:49 ` Greg KH
2021-04-21 9:06 ` Daniel Lezcano
2021-04-21 9:37 ` Tony Lindgren [this message]
2021-04-21 11:36 ` Daniel Lezcano
2021-04-22 12:39 ` 答复: " linruizhe
2021-04-22 13:50 ` Daniel Lezcano
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