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@xxxxxxxxxx> > Cc: Seungwon Jeon <tgih.jun@xxxxxxxxxxx> > Cc: Jaehoon Chung <jh80.chung@xxxxxxxxxxx> > Cc: Chris Ball <cjb@xxxxxxxxxx> Thanks, pushed to mmc-next for 3.10. - Chris. -- Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
