From a66706158d6bc4d9eb29c37852001f78f4c8989c Mon Sep 17 00:00:00 2001 From: Chip Coldwell Date: Fri, 8 Feb 2008 04:21:06 -0800 Subject: [PATCH] atmel_serial: add DMA support This patch is based on the DMA-patch by Chip Coldwell for the AT91/AT32 serial USARTS, with some tweaks to make it apply neatly on top of the other patches in this series. The RX and TX code has been moved to a tasklet and reworked a bit. Instead of depending on the ENDRX and TIMEOUT bits in CSR, we simply grab as much data as we can from the DMA buffers. I think this closes a race where the ENDRX bit is set after we read CSR but before we read RPR, although I haven't confirmed this. Similarly, the two TX handlers (ENDTX and TXBUFE) have been combined into one. Since the current code only uses a single TX buffer, there's no point in handling those interrupts separately. This also fixes a DMA sync bug in the original patch. [linux@bohmer.net: rebased onto irq-splitup patch] [hskinnemoen@atmel.com: moved to tasklet, fixed dma bug, misc cleanups] [hskinnemoen@atmel.com: atmel_serial dma: Misc fixes and cleanups] Signed-off-by: Remy Bohmer Signed-off-by: Haavard Skinnemoen Cc: Andrew Victor Tested-by: Marc Pignat Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed