From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga06.intel.com ([134.134.136.31]:27082 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751667AbcL0K6n (ORCPT ); Tue, 27 Dec 2016 05:58:43 -0500 From: Jani Nikula To: Hans de Goede , Daniel Vetter , Ville =?utf-8?B?U3lyasOkbMOk?= Cc: intel-gfx , dri-devel@lists.freedesktop.org, Hans de Goede , stable@vger.kernel.org Subject: Re: [PATCH] drm/i915: Fix not finding the VBT when it overlaps with OPREGION_ASLE_EXT In-Reply-To: <20161225101928.7618-1-hdegoede@redhat.com> References: <20161225101928.7618-1-hdegoede@redhat.com> Date: Tue, 27 Dec 2016 12:58:35 +0200 Message-ID: <87pokd4p0k.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org List-ID: On Sun, 25 Dec 2016, Hans de Goede wrote: > If there is no OPREGION_ASLE_EXT then a VBT stored in mailbox #4 may > use the ASLE_EXT parts of the opregion. Adjust the vbt_size calculation > for a vbt in mailbox #4 for this. > > This fixes the driver not finding the VBT on a jumper ezpad mini3 > cherrytrail tablet. Thanks for the patch. I think you're onto something, but I don't think the patch is quite correct. That said, I'm not sure myself yet what would be. ;) Without the change, does intel_bios_is_valid_vbt() return true anyway? I.e. do you get "Found valid VBT in ACPI OpRegion (Mailbox #4)\n" in log? If not, which of the debug messages in intel_bios_is_valid_vbt() do you get? In the latter case, I suspect you'll end up with failure in intel_bios.c with either "No MIPI config BDB found" or "No MIPI Sequence found, parsing complete\n". BR, Jani. > > Cc: stable@vger.kernel.org > Signed-off-by: Hans de Goede > --- > Note even with this fixed the panel still does not work with 4.9, > but it does with drm-intel-next-queued :) I believe the missing bit in > 4.9 is the "drm/915: Parsing the missed out DTD fields from the VBT" > commit, but I've not verified this. > --- > drivers/gpu/drm/i915/intel_opregion.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c > index f4429f6..eff35ae 100644 > --- a/drivers/gpu/drm/i915/intel_opregion.c > +++ b/drivers/gpu/drm/i915/intel_opregion.c > @@ -982,7 +982,9 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv) > opregion->vbt_size = vbt_size; > } else { > vbt = base + OPREGION_VBT_OFFSET; > - vbt_size = OPREGION_ASLE_EXT_OFFSET - OPREGION_VBT_OFFSET; > + vbt_size = (mboxes & MBOX_ASLE_EXT) ? > + OPREGION_ASLE_EXT_OFFSET : OPREGION_SIZE; > + vbt_size -= OPREGION_VBT_OFFSET; > if (intel_bios_is_valid_vbt(vbt, vbt_size)) { > DRM_DEBUG_KMS("Found valid VBT in ACPI OpRegion (Mailbox #4)\n"); > opregion->vbt = vbt; -- Jani Nikula, Intel Open Source Technology Center