From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Subject: Re: [PATCH] Revert "drm/i915: Preserve VGACNTR bits from the BIOS" Date: Tue, 16 Dec 2014 17:53:58 +0100 Message-ID: <20141216175358.65ade935@pluto.restena.lu> References: <1418747917-21349-1-git-send-email-ville.syrjala@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1418747917-21349-1-git-send-email-ville.syrjala@linux.intel.com> Sender: stable-owner@vger.kernel.org To: ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org, stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org Hi Ville, On Tue, 16 Dec 2014 18:38:37 +0200 ville.syrjala@linux.intel.com wrote: > From: Ville Syrj=C3=A4l=C3=A4 >=20 > 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. >=20 > The original reason for preserving the VGACNTR register was to make > my 830 survive S3 with acpi_sleep=3Ds3_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. >=20 > This reverts commit 69769f9a422bfc62e17399da3590c5e31ac37f24. > > Cc: bonbons67@internet.lu Please swap my old "bugzilla e-mail" address with Bruno Pr=C3=A9mont Thanks, Bruno > Cc: stable@vger.kernel.org > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=3D87171 > Signed-off-by: Ville Syrj=C3=A4l=C3=A4 > --- > drivers/gpu/drm/i915/i915_drv.h | 2 -- > drivers/gpu/drm/i915/intel_display.c | 8 +------- > 2 files changed, 1 insertion(+), 9 deletions(-) >=20 > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i= 915_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; > =20 > - uint32_t bios_vgacntr; > - > /* Old dri1 support infrastructure, beware the dragons ya fools ent= ering > * here! */ > struct i915_dri1_state dri1; > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i= 915/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_devi= ce *dev) > vga_put(dev->pdev, VGA_RSRC_LEGACY_IO); > udelay(300); > =20 > - /* > - * 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); > } > =20 > @@ -13026,8 +13022,6 @@ void intel_modeset_init(struct drm_device *de= v) > =20 > intel_shared_dpll_init(dev); > =20 > - /* save the BIOS value before clobbering it */ > - dev_priv->bios_vgacntr =3D I915_READ(i915_vgacntrl_reg(dev)); > /* Just disable it once at startup */ > i915_disable_vga(dev); > intel_setup_outputs(dev);