[PATCH 1/2] ARM: omapfb: add coherent dma memory support
From: Tomi Valkeinen <hidden>
Date: 2014-01-09 08:27:27
Also in:
linux-fbdev, linux-omap
On 2014-01-09 10:08, Hiremath, Vaibhav wrote:
No, that's what is causing issue to me. Can you try predefined address flow? Just to highlight, I get UNDERFLOW during boot itself, immediately when it gets mapped to userspace. Boot LOG:
[ 4.822549] Freeing unused kernel memory: 440K (c0919000 - c0987000) [ 5.276615] OMAPFB: pan_display(0) [ 5.276625] OMAPFB: setcmap [ 5.276635] OMAPFB: setcmap [ 5.293518] OMAPFB: user mmap region start a0000000, len 1536000, off 0 [ 5.300171] omapdss APPLY error: FIFO UNDERFLOW on gfx, disabling the overlay
Hmm that's interesting... So you have some tool that's ran early, which draws something on the screen? Or maybe that's X starting? Ah... I think I understand now. As I mentioned, AM4x has issues already. I think the CPU/others can block DSS when accessing memory. So, if we have bad caching for the mapped framebuffer, the CPU will use more bandwidth when reading/writing to it, and that will cause DSS to underflow. Tomi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 901 bytes Desc: OpenPGP digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140109/94e5177e/attachment-0001.sig>