mmc: sdhci: work around broken dma boundary behavior

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Some SD host controllers (noticed on an integrated JMicron SD reader on an
HP Pavilion dv5-1250eo laptop) don't update the dma address register before
signaling a dma interrupt due to a dma boundary. Update the register
manually to the next boundary (by default 512KiB), at which the transfer
stopped.

As long as each transfer is at most 512KiB in size (guaranteed by a BUG_ON
in sdhci_prepare_data()) and the boundary is kept at the default value,
this fix is needed at most once per transfer. Smaller boundaries are taken
care of by counting the transferred bytes.

Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=28462

Signed-off-by: Mikko Vinni <mmvinni@yahoo.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

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This commit is contained in:

Mikko Vinni 2011-04-12 09:36:18 -04:00 • committed by Chris Ball

parent 6f60c22252

commit f6a03cbf43

2 changed files with 31 additions and 5 deletions

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30

drivers/mmc/host/sdhci.c

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6

drivers/mmc/host/sdhci.h

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