Hi, On 06-02-17 08:04, Jani Nikula wrote:
On Sun, 25 Dec 2016, Hans de Goede <hdegoede@xxxxxxxxxx> 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. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- 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;First, I want a big fat warning comment about what's going on here. Otherwise someone's bound to "fix" this later on.
Done for v2, which I will send shortly.
Second, per the spec, the ASLE ext mailbox is 1k in size, and there's a 1k reserved region at the end. We probably shouldn't allow VBT to extend over there. But hey, per the spec we also shouldn't allow VBT to extend over mailbox #5 either. So if you can't be bothered with that, neither will I.
Hmm, that makes no sense, OPREGION_SIZE is 8192 bytes or 0x2000, OPREGION_ASLE_EXT_OFFSET is 0x1C00 or 7168 bytes, if there is 1k reserved after the ASLE ext mailbox then there is exactly 0 bytes available for the ASLE ext mailbox or OPREGION_SIZE should be 9216 not 8192 (which I don't think so). Maybe the last 1k is either the ASLE ext mailbox OR reserved ? Anyways leaving this bit as is for now. Regards, Hans -- 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