Re: [PATCH] phy: zynqmp: Fix unused-function compiler warning

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Tobias Klauser <tklauser@distanz.ch>
Cc: Vinod Koul <vkoul@kernel.org>,
	Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Michal Simek <michal.simek@xilinx.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] phy: zynqmp: Fix unused-function compiler warning
Date: Wed, 1 Jul 2020 17:09:13 +0300	[thread overview]
Message-ID: <20200701140913.GG27013@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20200701140709.kq7eauyrm5lqozsr@distanz.ch>

Hi Tobias,

On Wed, Jul 01, 2020 at 04:07:09PM +0200, Tobias Klauser wrote:
> On 2020-07-01 at 16:01:08 +0200, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> > On Wed, Jul 01, 2020 at 04:00:26PM +0200, Tobias Klauser wrote:
> >> On 2020-07-01 at 15:44:43 +0200, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> >>> On Wed, Jul 01, 2020 at 07:06:43PM +0530, Vinod Koul wrote:
> >>>> On 01-07-20, 16:19, Laurent Pinchart wrote:
> >>>>> On Wed, Jul 01, 2020 at 11:04:38AM +0200, Tobias Klauser wrote:
> >>>>>> This fixes the following compiler warning when building with
> >>>>>> CONFIG_PM && !CONFIG_PM_SLEEP:
> >>>>>> 
> >>>>>> drivers/phy/xilinx/phy-zynqmp.c:830:12: warning: ‘xpsgtr_resume’ defined but not used [-Wunused-function]
> >>>>>>   830 | static int xpsgtr_resume(struct device *dev)
> >>>>>>       |            ^~~~~~~~~~~~~
> >>>>>> drivers/phy/xilinx/phy-zynqmp.c:819:12: warning: ‘xpsgtr_suspend’ defined but not used [-Wunused-function]
> >>>>>>   819 | static int xpsgtr_suspend(struct device *dev)
> >>>>>>       |            ^~~~~~~~~~~~~~
> >>>>> 
> >>>>> Oops :-S Sorry about that.
> >>>>> 
> >>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >> 
> >> Thanks for the review Laurent.
> >> 
> >>>>> Vinod or Kishon, can you pick this patch up, or do I need to send a pull
> >>>>> request ? (It's my first driver in the PHY subsystem so I don't know
> >>>>> what the usual practices are there)
> >>>> 
> >>>> patches are welcome :-)
> >>>> 
> >>>>> 
> >>>>>> Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
> >>>>>> ---
> >>>>>>  drivers/phy/xilinx/phy-zynqmp.c | 4 ++--
> >>>>>>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>>>>> 
> >>>>>> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
> >>>>>> index 8babee2ce9ec..22a0ae635797 100644
> >>>>>> --- a/drivers/phy/xilinx/phy-zynqmp.c
> >>>>>> +++ b/drivers/phy/xilinx/phy-zynqmp.c
> >>>>>> @@ -815,7 +815,7 @@ static struct phy *xpsgtr_xlate(struct device *dev,
> >>>>>>   * Power Management
> >>>>>>   */
> >>>>>>  
> >>>>>> -#ifdef CONFIG_PM
> >>>>>> +#ifdef CONFIG_PM_SLEEP
> >>>> 
> >>>> How about marking it as __maybe_unused instead?
> >>> 
> >>> I don't mind either, I'll let Tobias decide, but his patch seems fine,
> >>> is there a drawback in his approach ? If it's just a matter of personal
> >>> preference, I'd rather not require a v2.
> >> 
> >> I don't mind either, it was just what seemed the more straight-forward
> >> fix. On the other hand, it seems that marking these functions as
> >> __maybe_unused is the more widely used method in other PHY drivers. In
> >> addition it would have the nice side-effect of the code always being
> >> compile-checked regardless of the value of CONFIG_PM_SLEEP.
> > 
> > That's a good point, haven't thought about it.
> > 
> >> Will send a v2 using __maybe_unused and will let you decide which one to
> >> pick :)
> > 
> > You can keep my R-b :-)
> 
> Thanks :) FWIW, I'd also drop the #ifdef CONFIG_PM in the same patch for
> the same reason. Is that OK with you as well?

Sure.

-- 
Regards,

Laurent Pinchart