Messages in this thread | | | From | Chris Ball <> | Subject | Re: [PATCH 3/3] dw_mmc: Handle unaligned data submission correctly | Date | Fri, 22 Mar 2013 12:52:12 -0400 |
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Hi,
On Tue, Mar 12 2013, Markos Chandras wrote: > Commit f9c2a0dc42a6938ff2a80e55ca2bbd1d5581c72e > "mmc: dw_mmc: Fix PIO mode with support of highmem" introduced > a regression since v3.2 making the mmc_test hang on test #13 > with a "Data starvation by host timeout" interrupt. > > This is because, sg_mapping_iter is used to iterate through the > data which spans on multiple pages. The problem is detected on > unaligned data submission where the code previously checked for > !(sg_next(host->sg)) which is true because we only have a single > scatter/gather list which then expands to multiple pages. > Therefore, the driver incorrectly assumed that this was the last > list item and submitted unaligned data to the mmc device. This > overflowed the FIFO on the device before all the data were written > to it. The code was fixed to only submit unaligned data when we are > handling the last sg_miter item by checking whether we reached > the desired data length or not. > > The patch was tested against mmc_test and all the tests passed. > > Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> > Cc: Seungwon Jeon <tgih.jun@samsung.com> > Cc: Jaehoon Chung <jh80.chung@samsung.com> > Cc: Chris Ball <cjb@laptop.org>
Thanks, pushed to mmc-next for 3.10.
- Chris. -- Chris Ball <cjb@laptop.org> <http://printf.net/> One Laptop Per Child
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