On Tue, 2010-07-27 at 09:34 +0200, ext Taneja, Archit wrote: > > > > Looks ok to me, I'll add it to my tree. Are you actually > > using dsi_update_screen_l4? > > > > Tomi > > There is a usecase in OMAP4 where we can run 4 displays in > parallel, 3 can be run using the 3 dispc channels, and another DSI > panel can be run using L4 updates. Ok. > It would probably be better if we can connect 2 or more peripherals to > one DSI PHY, but with l4 updates we don't need to introduce any hardware changes > on the boards. > > So with l4 update we can free one dispc channel. I am not sure how much the > 4 display usecase is going to be used. But having l4 updates is still a handy feature, The current implementation of dsi_update_screen_l4() is very bad performance-wise, for throughput and for being basically a busy loop. Much better would be to use system DMA for the transfer. In theory this is possible, and I've made some tests with it, but I wasn't able to solve the problems how to inject DSI commands (write_memory_start and write_memory_continue), and how to get unpacked 24bit pixels from the memory changed into packed 24bit pixels for the DSI transfer. > especially if one wants to run both a DPI and a DSI display on OMAP3 :) Yes, that's the original reason I implemented it =). Tomi -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
