From mboxrd@z Thu Jan 1 00:00:00 1970 From: Imre Deak Subject: Re: [PATCH] drm/i915: dsi: fix pipe-off timeout due to port vs. pipe disable ordering Date: Tue, 27 May 2014 18:53:37 +0300 Message-ID: <1401206017.10798.69.camel@intelbox> References: <1401196539-17715-1-git-send-email-imre.deak@intel.com> <53849DF7.4040403@intel.com> <1401203550.10798.61.camel@intelbox> <5384B090.7050101@intel.com> Reply-To: imre.deak@intel.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1619604691==" Return-path: Received: from mga03.intel.com (mga03.intel.com [143.182.124.21]) by gabe.freedesktop.org (Postfix) with ESMTP id 944CC6E756 for ; Tue, 27 May 2014 08:54:02 -0700 (PDT) In-Reply-To: <5384B090.7050101@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: "Kumar, Shobhit" Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org --===============1619604691== Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-L5MBp06oaEUTaY/wZp/c" --=-L5MBp06oaEUTaY/wZp/c Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2014-05-27 at 21:04 +0530, Kumar, Shobhit wrote: > On 5/27/2014 8:42 PM, Imre Deak wrote: > > On Tue, 2014-05-27 at 19:45 +0530, Kumar, Shobhit wrote: > >> On 5/27/2014 6:45 PM, Imre Deak wrote: > >>> If we disable first the port (by disabling DPI) and only then the > >>> display pipe the pipe-off flag will never be set, possibly leading to= a > >>> hanged pipe state at the next modeset-enable. > >>> > >>> Note that according to the VLV2 display cluster HAS, we should disabl= e > >>> the port before the pipe. This doesn't seem to match reality based on > >>> the above and it's also asymmetric with the enabling sequence, where = we > >>> first enable the port and then the pipe. > >>> > >>> Signed-off-by: Imre Deak > >>> --- > >>> drivers/gpu/drm/i915/intel_dsi.c | 9 ++++++++- > >>> 1 file changed, 8 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/= intel_dsi.c > >>> index e73bec6..3756af1 100644 > >>> --- a/drivers/gpu/drm/i915/intel_dsi.c > >>> +++ b/drivers/gpu/drm/i915/intel_dsi.c > >>> @@ -206,6 +206,11 @@ static void intel_dsi_enable_nop(struct intel_en= coder *encoder) > >>> */ > >>> } > >>> > >>> +static void intel_dsi_disable_nop(struct intel_encoder *encoder) > >>> +{ > >>> + DRM_DEBUG_KMS("\n"); > >>> +} > >>> + > >> > >> Make this as *_pre_disable and the SHUTDOWN command should be sent in > >> this function. That is the recommended sequence in disable path. First > >> thing is to shutdown the panel. Remove that bit from the intel_dsi_dis= able. > > > > I tried this, but it results in a "Timeout waiting for DPI FIFO empty" > > error when sending the SHUTDOWN command. This order would be also > > asymmetric with the enabling sequence where we first turn on the panel > > and only then enable the pipe. So I would need more explanation for the > > above before moving the SHUTDOWN command earlier. > > > I think checking DPI FIFO empty before sending DPI commands is wrong.=20 > Unless pipe is stopped DPI FIFO will not be empty. Basically we should= =20 > test for DPI FIFO full in case of error. I was planning to look into=20 > that correction. Ok, makes sense, I'll update the patch. --Imre --=-L5MBp06oaEUTaY/wZp/c Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) iQEcBAABAgAGBQJThLUBAAoJEORIIAnNuWDFOqwH/igEGULmkpRYttCljJXhl6pe 62gUnbuBEtvr70tcDSZPWNrR+UhejowgDgoPhGK2aA+JpkiSmlZ/f8T6QRDedUr4 za07ubpBZIPQ7hm1+xEUBChdRF8Rfez1mBixEokhgCi6o5VKHJPSLTC2qgM8arHu wZilUuTNAIS5dWz5p1BbdsM0msHkZy/mF0CnzZzvvNMOOXN6mXvyv3dWt0Y03uhr 03P6smO/czrGb8YMJi4miwFDJ+q5lLqAmELU33bCakXO6v4pKeiAQK3t1wvgkM74 PJCMa6Qz8fXWwdHgbMMwMP3ussZRwBjEnftlj06HpNCaM4MtDgrAu+ZI0Vs5fHI= =krnT -----END PGP SIGNATURE----- --=-L5MBp06oaEUTaY/wZp/c-- --===============1619604691== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx --===============1619604691==--