[PATCH 2/6] mmc: bcm2835: Increase max_blk_size to 1024

Stefan Wahren stefan.wahren at i2se.com
Wed Feb 15 12:32:11 PST 2017

Hi Eric,

> Eric Anholt <eric at anholt.net> hat am 14. Februar 2017 um 22:37 geschrieben:
> Eric Anholt <eric at anholt.net> writes:
> > [ Unknown signature status ]
> > Stefan Wahren <stefan.wahren at i2se.com> writes:
> >
> >> In order to use the same max_blk_size like the sdhci-iproc does
> >> we need to increase it to 1024 bytes. This results in a
> >> little write performance gain for MMC:
> >
> > I'm confused -- this series is for SDHOST, right?  Why are you comparing
> > to sdhci-iproc (the EMMC controller), then?
> That said, I see no restrictions on block length in the hw (it's a
> 32-bit register stored by CMD16).

yes the SDHOST has nothing to do with eMMC controller. But i tested the value above with the eMMC on the CM and the SDHOST driver, because SD cards usually operates only with 512 bytes block size and won't benefit from a higher value. Naming the Arasan eMMC controller and the other SDHOST wasn't the best decision. Both should be able to handle SD cards, eMMC and SDIO. I also tested higher values but the performance gain wasn't remarkable. In order to keep it easy it decided to choose the same values as sdhci-iproc.


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