From mboxrd@z Thu Jan 1 00:00:00 1970 From: sam@ravnborg.org (Sam Ravnborg) Date: Mon, 17 Sep 2018 21:37:48 +0200 Subject: [RESEND 4/5] drm/mxsfb: Add PM_SLEEP support In-Reply-To: <7d661819825a36f4aebe412e7bed8fe24c7292ae.1535367027.git.leonard.crestez@nxp.com> References: <7d661819825a36f4aebe412e7bed8fe24c7292ae.1535367027.git.leonard.crestez@nxp.com> Message-ID: <20180917193748.GA13165@ravnborg.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Leonard. On Mon, Aug 27, 2018 at 02:10:40PM +0300, Leonard Crestez wrote: > Since power to the lcdif block can be lost on suspend implement > PM_SLEEP_OPS using drm_mode_config_helper_suspend/resume to save/restore > the current mode. > > Signed-off-by: Leonard Crestez > Reviewed-by: Stefan Agner > --- > drivers/gpu/drm/mxsfb/mxsfb_drv.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > index 68d79f5dc0d3..d797dfd40d98 100644 > --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > @@ -416,17 +416,38 @@ static int mxsfb_remove(struct platform_device *pdev) > drm_dev_unref(drm); > > return 0; > } > > +#ifdef CONFIG_PM_SLEEP > +static int mxsfb_suspend(struct device *dev) > +{ > + struct drm_device *drm = dev_get_drvdata(dev); > + > + return drm_mode_config_helper_suspend(drm); > +} > + > +static int mxsfb_resume(struct device *dev) > +{ > + struct drm_device *drm = dev_get_drvdata(dev); > + > + return drm_mode_config_helper_resume(drm); > +} > +#endif Other suspend/resume users skip the #ifdef and declare the functions __maybe_unused See for example arm/hdlcd_drv.c. The resulting code is a bit simpler to read and you have the added benefit that the suspend/resume functions are always compiled so bit-rotting is less likely. Sam