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- "Levin, Alexander (Sasha Levin)"
- Mark Brown
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
- "Levin, Alexander (Sasha Levin)"
| | | From | "Levin, Alexander (Sasha Levin)" <> | Subject | Re: [PATCH AUTOSEL for-4.9 04/53] spi: imx: adjust watermark level according to transfer length | Date | Wed, 8 Nov 2017 21:39:11 +0000 |
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On Wed, Nov 08, 2017 at 08:57:52PM +0000, Mark Brown wrote: >On Wed, Nov 08, 2017 at 08:49:55PM +0000, Levin, Alexander (Sasha Levin) wrote: >> From: Jiada Wang <jiada_wang@mentor.com> >> >> [ Upstream commit 66459c5a50a787c474b734b586328f7111ab6df0 ] >> >> Previously DMA watermark level is configured to fifosize/2, >> DMA mode can be used only when transfer length can be divided >> by 'watermark level * bpw', which makes DMA mode not pratical. >> >> This patch adjusts watermark level to largest number (no bigger >> than fifosize/2) which can divide 'tranfer length / bpw' for >> each transfer. > >This seems like an optimization not a bug fix...
Hm, is it? I read it as "DMA is not being used at all even though we thought we're using it".
Yes, the impact is "just" performance, but doesn't it result in quite a significat impact?
--
Thanks, Sasha
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