From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Fri, 9 May 2014 07:37:49 -0700 Subject: [PATCH 1/4] OMAPDSS: Fix DSS clock multiplier issue on 3703 and probably 3630 In-Reply-To: <536C8B70.1000306@ti.com> 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> Message-ID: <20140509143748.GB17814@atomide.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org * 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/dss/dss.c:483 dss_set_fck_rate+0x6c/0x8c() > > [ 3.538360] clk rate mismatch: 108000000 != 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? OK pasted to the other email in this thread. Tony