| Date | Thu, 9 Apr 2015 17:37:03 +0800 | Subject | Re: [PATCH 3.4 115/176] spi: dw: Fix detecting FIFO depth | From | Axel Lin <> |
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2015-04-09 16:46 GMT+08:00 <lizf@kernel.org>: > From: Axel Lin <axel.lin@ingics.com> > > 3.4.107-rc1 review patch. If anyone has any objections, please let me know. > > ------------------ > > > commit d297933cc7fcfbaaf2d37570baac73287bf0357d upstream. > > Current code tries to find the highest valid fifo depth by checking the value > it wrote to DW_SPI_TXFLTR. There are a few problems in current code: > 1) There is an off-by-one in dws->fifo_len setting because it assumes the latest > register write fails so the latest valid value should be fifo - 1. > 2) We know the depth could be from 2 to 256 from HW spec, so it is not necessary > to test fifo == 257. In the case fifo is 257, it means the latest valid > setting is fifo = 256. So after the for loop iteration, we should check > fifo == 2 case instead of fifo == 257 if detecting the FIFO depth fails. > This patch fixes above issues. > > Signed-off-by: Axel Lin <axel.lin@ingics.com> > Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Signed-off-by: Mark Brown <broonie@kernel.org> > [lizf: Backported to 3.4: adjust context] > Signed-off-by: Zefan Li <lizefan@huawei.com>
Hi, This patch needs below fix: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/spi/spi-dw.c?id=9d239d353c319f9ff884c287ce47feb7cdf60ddc
Thanks, Axel
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