Hi Andrei..
Did you test this patch with ADMA? I wonder that be increased performance or others..
Regards, Jaehoon Chung
Andrei Warkentin wrote:
Hi Shawn,
On Sat, Apr 16, 2011 at 11:48 AM, Shawn Guo shawn.guo@linaro.org wrote:
pre_req() runs dma_map_sg() post_req() runs dma_unmap_sg. If not calling pre_req() before sdhci_request(), request() will prepare the cache just like it did it before. It is optional to use pre_req() and post_req().
Signed-off-by: Shawn Guo shawn.guo@linaro.org
I worked out the patch by referring to Per's patch below.
omap_hsmmc: add support for pre_req and post_req
It adds pre_req and post_req support for sdhci based host drivers to work with Per's non-blocking optimization. But I only have imx esdhc based hardware to test. Unfortunately, I can not measure the performance gain using mmc_test, because the current esdhc driver on mainline fails on the test. So I just did a quick test using 'dd', but sadly, I did not see noticeable performance gain here. The followings are possible reasons I can think of right away.
- The patch did not add pre_req and post_req correctly. Please help
review to catch the mistakes if any.
- The imx esdhc driver uses SDHCI_SDMA (max_segs is 1) than SDHCI_ADAM
(max_segs is 128), due to the broken ADMA support on imx esdhc. So can people holding other sdhci based hardware give a try on the patch?
Hopefully, I can find some time to have a close look at the mmc_test failure and the broken ADMA with imx esdhc.
I'll try it out...
A
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