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author | Chip Coldwell <coldwell@redhat.com> | 2008-02-08 13:21:06 +0100 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-08 18:22:37 +0100 |
commit | a66706158d6bc4d9eb29c37852001f78f4c8989c (patch) | |
tree | d2d593dc2902c1db1ea6d0ef417dc3426e0b3bae /init | |
parent | atmel_serial: split the interrupt handler (diff) | |
download | linux-a66706158d6bc4d9eb29c37852001f78f4c8989c.tar.xz linux-a66706158d6bc4d9eb29c37852001f78f4c8989c.zip |
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 <linux@bohmer.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
Tested-by: Marc Pignat <marc.pignat@hevs.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions