| Message ID | 20161121181616.GN1041@n2100.armlinux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 21, 2016 at 06:16:16PM +0000, Russell King - ARM Linux wrote: > On Mon, Nov 21, 2016 at 05:56:02PM +0000, Russell King - ARM Linux wrote: > > For me, the image shift was 100% reproducable. With the above patch > > and a call to drm_crtc_vblank_on() in the enable path, it seems to > > behave correctly - I can alternately switch between 1920x1080 and > > 1280x1024 and it behaves correctly. Indeed, my debug prints show that > > the right thing is happening wrt disabling the controller: > > Here's my version of your patch: Thanks! I'll add it to my tree and see if David Airlie is happy to push it this late into the release cycle. Otherwise it is going to end up in linux-next quickly and then in drm-next before v4.10. > > 8<============= > From: Russell King <rmk+kernel@armlinux.org.uk> > Subject: [PATCH] drm/arm: hdlcd: fix plane base address update > > While testing HDMI with Xorg on the Juno board, I find that when Xorg > starts up or shuts down, the display is shifted significantly to the > right and wrapped in the active region. (No sync bars are visible.) > The timings are correct, it behaves as if the start address has been > shifted many pixels _into_ the framebuffer. > > This occurs whenever the display mode size is changed - using xrandr > in Xorg shows that changing the resolution triggers the problem > almost every time, but changing the refresh rate does not. > > Using devmem2 to disable and re-enable the HDLCD resolves the issue, > and repeated disable/enable cycles do not make the issue re-appear. > Further debugging shows that we try to update the controller > configuration while enabled. > > Alwys ensure that the HDLCD is disabled prior to updating the > controller timings, and use drm_crtc_vblank_off()/drm_crtc_vblank_on() > so that DRM knows whether it can expect vblank interrupts. > > Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Liviu Dudau <Liviu.Dudau@arm.com> > --- > drivers/gpu/drm/arm/hdlcd_crtc.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c > index c239616f5334..9d683be2e5d3 100644 > --- a/drivers/gpu/drm/arm/hdlcd_crtc.c > +++ b/drivers/gpu/drm/arm/hdlcd_crtc.c > @@ -151,15 +151,14 @@ static void hdlcd_crtc_enable(struct drm_crtc *crtc) > clk_prepare_enable(hdlcd->clk); > hdlcd_crtc_mode_set_nofb(crtc); > hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1); > + drm_crtc_vblank_on(crtc); > } > > static void hdlcd_crtc_disable(struct drm_crtc *crtc) > { > struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc); > > - if (!crtc->state->active) > - return; > - > + drm_crtc_vblank_off(crtc); > hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0); > clk_disable_unprepare(hdlcd->clk); > } > -- > 2.7.4 > > -- > RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up > according to speedtest.net.
diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c index c239616f5334..9d683be2e5d3 100644 --- a/drivers/gpu/drm/arm/hdlcd_crtc.c +++ b/drivers/gpu/drm/arm/hdlcd_crtc.c @@ -151,15 +151,14 @@ static void hdlcd_crtc_enable(struct drm_crtc *crtc) clk_prepare_enable(hdlcd->clk); hdlcd_crtc_mode_set_nofb(crtc); hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1); + drm_crtc_vblank_on(crtc); } static void hdlcd_crtc_disable(struct drm_crtc *crtc) { struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc); - if (!crtc->state->active) - return; - + drm_crtc_vblank_off(crtc); hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0); clk_disable_unprepare(hdlcd->clk); }