On Mon, 19 Jan 2015, Bruno Prémont <bonbons@xxxxxxxxxxxxxxxxx> wrote: > Hi Greg, stable team, > > Please find below the back-ported patch (only a little bit of fuzz and > changed offsets to handle). > Patch applies cleanly on top of v3.18.3. Thanks Bruno, FWIW this is Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> > > Thanks, > Bruno > > > > From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx> > Date: Tue, 16 Dec 2014 18:38:37 +0200 > Subject: [PATCH] Revert "drm/i915: Preserve VGACNTR bits from the BIOS" > MIME-Version: 1.0 > Content-Type: text/plain; charset=UTF-8 > Content-Transfer-Encoding: 8bit > > Commit 01f5a6261cea395f72877aeb7c2fe2d42e1b1e00 upstream. > > The VGA_2X_MODE bit apparently affects the display even when the VGA > plane is disabled. The bit will set by the BIOS when the panel width > is at least 1280 pixels. So by preserving the bit from the BIOS we > end up with corrupted display on machines with such high res panels. > I only have 1024x768 panels on my gen2 machines so never ran into > this problem. > > The original reason for preserving the VGACNTR register was to make > my 830 survive S3 with acpi_sleep=s3_bios option. However after > further 830 fixes that option is no longer needed to make S3 work > and preserving VGACNTR doesn't seem to be necessary without it, > so we can just revert the entire patch. > > This reverts > commit 69769f9a422bfc62e17399da3590c5e31ac37f24 > Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Date: Fri Aug 15 01:22:08 2014 +0300 > > drm/i915: Preserve VGACNTR bits from the BIOS > > Cc: Bruno Prémont <bonbons@xxxxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=87171 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > --- > drivers/gpu/drm/i915/i915_drv.h | 2 -- > drivers/gpu/drm/i915/intel_display.c | 8 +------- > 2 files changed, 1 insertion(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 16a6f6d..fd2d433 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -1665,8 +1665,6 @@ struct drm_i915_private { > */ > struct workqueue_struct *dp_wq; > > - uint32_t bios_vgacntr; > - > /* Old dri1 support infrastructure, beware the dragons ya fools entering > * here! */ > struct i915_dri1_state dri1; > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 9cb5c95..cadc3bc 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -12933,11 +12933,7 @@ static void i915_disable_vga(struct drm_device *dev) > vga_put(dev->pdev, VGA_RSRC_LEGACY_IO); > udelay(300); > > - /* > - * Fujitsu-Siemens Lifebook S6010 (830) has problems resuming > - * from S3 without preserving (some of?) the other bits. > - */ > - I915_WRITE(vga_reg, dev_priv->bios_vgacntr | VGA_DISP_DISABLE); > + I915_WRITE(vga_reg, VGA_DISP_DISABLE); > POSTING_READ(vga_reg); > } > > @@ -13026,8 +13022,6 @@ void intel_modeset_init(struct drm_device *dev) > > intel_shared_dpll_init(dev); > > - /* save the BIOS value before clobbering it */ > - dev_priv->bios_vgacntr = I915_READ(i915_vgacntrl_reg(dev)); > /* Just disable it once at startup */ > i915_disable_vga(dev); > intel_setup_outputs(dev); -- Jani Nikula, Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html