From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Mon, 12 May 2014 11:38:04 +0000 Subject: Re: [PATCH 1/4] OMAPDSS: Fix DSS clock multiplier issue on 3703 and probably 3630 Message-Id: <5370B29C.6040206@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="CqOCQgB4rTI87txxnj5RRexNEUpDCUcvt" List-Id: References: <1398815562-24113-1-git-send-email-tony@atomide.com> <1398815562-24113-2-git-send-email-tony@atomide.com> <20140508232006.GG2198@atomide.com> <536C8B70.1000306@ti.com> <20140509143748.GB17814@atomide.com> In-Reply-To: <20140509143748.GB17814@atomide.com> To: linux-arm-kernel@lists.infradead.org --CqOCQgB4rTI87txxnj5RRexNEUpDCUcvt Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 09/05/14 17:37, Tony Lindgren wrote: > * Tomi Valkeinen [140509 01:02]: >> On 09/05/14 02:20, Tony Lindgren wrote: >>> * Tony Lindgren [140429 16:53]: >>>> Otherwise we can get often errors like the following and the >>>> display won't come on: >>>> >>>> omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay >>>> omapdss APPLY error: SYNC_LOST on channel lcd, restarting >>>> the output with video overlays disabled >>>> >>>> There are some earlier references to this issue: >>>> >>>> http://www.spinics.net/lists/linux-omap/msg59511.html >>>> http://www.spinics.net/lists/linux-omap/msg59724.html >>>> >>>> It seems that it's safe to set the lower values even for 3630. >>>> If we can confirm that 3630 works with the higher values >>>> reliably we can add further detection. >>> >>> BTW, I'm also seeing this warning on 3730-evm it may be related: >>> >>> [ 3.523101] ------------[ cut here ]------------ >>> [ 3.528015] WARNING: CPU: 0 PID: 6 at drivers/video/fbdev/omap2/ds= s/dss.c:483 dss_set_fck_rate+0x6c/0x8c() >>> [ 3.538360] clk rate mismatch: 108000000 !=3D 115200000 >>> [ 3.543518] Modules linked in: >> >> Hmm... Can you paste the clk_summary from debugfs? Somehow the clock >> framework calculates the clock rate differently than the dss. Or do we= >> have different clock.dts files used for 3730 and 3630? >=20 > OK pasted to the other email in this thread. I mean the debugs for clock framework. The above warning means that the clock framework says the clock rate is X, but the dss had calculated that it should be Y. So there's a difference how the clock framework calculates the rate and how the dss calculates it. And yes, dss shouldn't calculate it. But I don't know how to get good pixel clocks if we didn't. Tomi --CqOCQgB4rTI87txxnj5RRexNEUpDCUcvt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJTcLKcAAoJEPo9qoy8lh71qGAP/ifuGZguN3b5z1hKVmrVulfZ DxodmAcVAHFs/iYEfDnK/pyAdJiZ6ngaVy2UoVwqLwzZlhWUCFVkbiBMmxZfZXP/ eh4w4gxLaMGHbeXNMKPbQGhilAS73z27KH8ytZ/A2TfRu38QHLJNyPGRmi2eh0Cl D6+Kn94Fdz+K7q+Zp1FRIPGSK0E4sMAK4IjuZjKHMLkw9eVyqsaL5EQzJAwZsswS fgblkasT6UFLDBK5F1CY7It17JOVrigicpGCNDrEANAtN94UXE0klt9zZ/uTwgB2 vXoVxR4olW/AVFk+IFlghUqVdp1zH32SeoigsRlZ0h0RfDp6/jtHGrTVhQd48XjW 0CFxNRM1hDGIqYBNNTh2TOJAik3g9Q3WXnosdfwuTDq/f/b+vOSyQEpTY4mcS1mW KP6gOlXQlMogAipZMClpi+CcSOOPGC2cAoUVIOnq35SFOACU8vUUl0wpZCZ/Q5mz aJKoQDmvfFTvkW1vI+fg9Yvr7qiKSQtoHn4irMCCXcYf2RqdTaAXYZQBN4+U5bog 0/+HxAFMa/Lyr9b1oS5lIEPZGp23c55gCPzU5+IM0++S5Wl2/zeydvuft1GX+VYZ j8IS0u+S6zpoCqdhahxC1oLIo1Qzhq8fGqsXSkXcWF8S+I55plcf/C50Tj7PgEXl Yg4EiykwIv2MX6Vu/4D7 =Qo1R -----END PGP SIGNATURE----- --CqOCQgB4rTI87txxnj5RRexNEUpDCUcvt--