> -----Original Message----- > From: Tomi Valkeinen [mailto:tomi.valkei...@nokia.com] > Sent: Wednesday, April 21, 2010 4:40 PM > To: Hiremath, Vaibhav > Cc: linux-omap@vger.kernel.org > Subject: RE: [PATCH] OMAP: DSS2: GFX FIFO UNDERFLOW issue fixed > > On Wed, 2010-04-21 at 12:45 +0200, ext Hiremath, Vaibhav wrote: > > > -----Original Message----- > > > From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap- > > > ow...@vger.kernel.org] On Behalf Of Hiremath, Vaibhav > > > Sent: Friday, April 16, 2010 4:28 PM > > > To: Tomi Valkeinen > > > Cc: linux-omap@vger.kernel.org > > > Subject: RE: [PATCH] OMAP: DSS2: GFX FIFO UNDERFLOW issue fixed > > > > > > > > > > -----Original Message----- > > > > From: Tomi Valkeinen [mailto:tomi.valkei...@nokia.com] > > > > Sent: Friday, April 16, 2010 3:08 PM > > > > To: Hiremath, Vaibhav > > > > Cc: linux-omap@vger.kernel.org > > > > Subject: Re: [PATCH] OMAP: DSS2: GFX FIFO UNDERFLOW issue fixed > > > > > > > > On Mon, 2010-03-22 at 14:09 +0100, ext hvaib...@ti.com wrote: > > > > > From: Vaibhav Hiremath <hvaib...@ti.com> > > > > > > > > > > In case of 720P with 90/270 degree rotation, the system reports > > > > > GFX_FIFO_UNDERFLOW error which usually happens if DSS DMA is not > able to > > > > fill > > > > > the FIFO as per requirement. > > > > > > > > > > In TRM (section 11.2.6.1.3), where is has been clearly mentioned > that, > > > > > > > > > > "To improve the performance on 90 degree rotation, split the data > access > > > > on > > > > > write side and not read side." > > > > > > > > > > That means, read should always happen on 0 degree and write should > go to > > > > > respective rotation view. > > > > > > > > > > > > > With this patch my db test app (from > > > > git://gitorious.org/linux-omap-dss2/omapfb-tests.git) shows a lot of > > > > tearing when rotation != 0. I tested this on 3430SDP using the LCD. > > [Hiremath, Vaibhav] Tomi, > > > > Yes, just now I tried your db application and I am also seeing tearing > effect. All other apps (including the one which I used for testing) works > fine for other rotation angles. > > > > Let me debug further before commenting anything on this, I just thought of > updating you on this. > > "db" app uses double buffering for updating the display, with maximum > update rate. There's also "pan" app, that does a bit similar thing using > fb offsets. > > What kind of test apps you have? > > Tomi > [Hiremath, Vaibhav] Just thought of updating you,
I had a good review of the db.c code and I don't see any issues with this, so somewhere VRFB related issue which I am missing. The only difference between db.c and pan.c (also my applications), it doesn't write/fill the entire buffer in pan loop everytime, whereas db.c file does. I think I need to take a look at the patch and TRM once again for this issue. Thanks, Vaibhav -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
