Re: [PATCH] omapdrm: dss: mark runtime PM functions __maybe_unused

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Tomi Valkeinen <tomba@kernel.org>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	Cai Huoqing <caihuoqing@baidu.com>, Arnd Bergmann <arnd@arndb.de>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Jyri Sarha <jsarha@ti.com>,
	Sebastian Reichel <sebastian.reichel@collabora.com>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] omapdrm: dss: mark runtime PM functions __maybe_unused
Date: Mon, 6 Dec 2021 13:14:56 +0200	[thread overview]
Message-ID: <Ya3wsKEVEtkTsmSU@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20211205131612.3192652-1-arnd@kernel.org>

Hi Arnd,

Thank you for the patch.

On Sun, Dec 05, 2021 at 02:15:56PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Using the SET_RUNTIME_PM_OPS() macro causes a warning about the
> referenced functions when they are marked static but not __maybe_unused:
> 
> drivers/gpu/drm/omapdrm/dss/dss.c:1572:12: error: unused function 'dss_runtime_suspend' [-Werror,-Wunused-function]
> drivers/gpu/drm/omapdrm/dss/dss.c:1584:12: error: unused function 'dss_runtime_resume' [-Werror,-Wunused-function]
> drivers/gpu/drm/omapdrm/dss/dispc.c:4845:12: error: unused function 'dispc_runtime_suspend' [-Werror,-Wunused-function]
> drivers/gpu/drm/omapdrm/dss/dispc.c:4860:12: error: unused function 'dispc_runtime_resume' [-Werror,-Wunused-function]
> 
> Fixes: b92f7ea556f8 ("drm/omap: dss: Make use of the helper macro SET_RUNTIME_PM_OPS()")

I wonder how well drivers are tested with !CONFIG_PM. We may be going
through hoops and loops to support this when it actually won't work in
most drivers. That's a separate issue though :-)

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Tomi, could you apply this ?

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/gpu/drm/omapdrm/dss/dispc.c | 4 ++--
>  drivers/gpu/drm/omapdrm/dss/dsi.c   | 4 ++--
>  drivers/gpu/drm/omapdrm/dss/dss.c   | 4 ++--
>  drivers/gpu/drm/omapdrm/dss/venc.c  | 4 ++--
>  4 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c
> index b440147ae28b..ab259efe132b 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dispc.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dispc.c
> @@ -4842,7 +4842,7 @@ static int dispc_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int dispc_runtime_suspend(struct device *dev)
> +static __maybe_unused int dispc_runtime_suspend(struct device *dev)
>  {
>  	struct dispc_device *dispc = dev_get_drvdata(dev);
>  
> @@ -4857,7 +4857,7 @@ static int dispc_runtime_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int dispc_runtime_resume(struct device *dev)
> +static __maybe_unused int dispc_runtime_resume(struct device *dev)
>  {
>  	struct dispc_device *dispc = dev_get_drvdata(dev);
>  
> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> index d730bf67fed9..a6845856cbce 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> @@ -5058,7 +5058,7 @@ static int dsi_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int dsi_runtime_suspend(struct device *dev)
> +static __maybe_unused int dsi_runtime_suspend(struct device *dev)
>  {
>  	struct dsi_data *dsi = dev_get_drvdata(dev);
>  
> @@ -5071,7 +5071,7 @@ static int dsi_runtime_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int dsi_runtime_resume(struct device *dev)
> +static __maybe_unused int dsi_runtime_resume(struct device *dev)
>  {
>  	struct dsi_data *dsi = dev_get_drvdata(dev);
>  
> diff --git a/drivers/gpu/drm/omapdrm/dss/dss.c b/drivers/gpu/drm/omapdrm/dss/dss.c
> index 66db28bfe824..69b3e15b9356 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dss.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dss.c
> @@ -1569,7 +1569,7 @@ static void dss_shutdown(struct platform_device *pdev)
>  	DSSDBG("shutdown\n");
>  }
>  
> -static int dss_runtime_suspend(struct device *dev)
> +static __maybe_unused int dss_runtime_suspend(struct device *dev)
>  {
>  	struct dss_device *dss = dev_get_drvdata(dev);
>  
> @@ -1581,7 +1581,7 @@ static int dss_runtime_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int dss_runtime_resume(struct device *dev)
> +static __maybe_unused int dss_runtime_resume(struct device *dev)
>  {
>  	struct dss_device *dss = dev_get_drvdata(dev);
>  	int r;
> diff --git a/drivers/gpu/drm/omapdrm/dss/venc.c b/drivers/gpu/drm/omapdrm/dss/venc.c
> index 508fddd376cf..4480b69ab5a7 100644
> --- a/drivers/gpu/drm/omapdrm/dss/venc.c
> +++ b/drivers/gpu/drm/omapdrm/dss/venc.c
> @@ -879,7 +879,7 @@ static int venc_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int venc_runtime_suspend(struct device *dev)
> +static __maybe_unused int venc_runtime_suspend(struct device *dev)
>  {
>  	struct venc_device *venc = dev_get_drvdata(dev);
>  
> @@ -889,7 +889,7 @@ static int venc_runtime_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int venc_runtime_resume(struct device *dev)
> +static __maybe_unused int venc_runtime_resume(struct device *dev)
>  {
>  	struct venc_device *venc = dev_get_drvdata(dev);
>  

-- 
Regards,

Laurent Pinchart