> From: John Troy <j...@noxi.us> > Date: Fri, 29 Apr 2016 11:56:24 -0400 > > On 4/28/16 2:30 PM, Mark Kettenis wrote: > > So here are just the bits that add DMA support. Since Theo likes this > > so much, I'd like to move forward with this. > > > > ok? > > > Hi Mark, > This diff seems to break things on my Lenovo Ideapad 100s. The 100s has > an internal eMMC and a microSD card slot. As far as I can tell, reading > from a microSD card breaks both eMMC and microSD. > > Reading from the eMMC, twice for good measure: > # dd if=/dev/rsd0c of=/dev/null bs=1M count=1 > 1+0 records in > 1+0 records out > 1048576 bytes transferred in 0.191 secs (5486853 bytes/sec) > # dd if=/dev/rsd0c of=/dev/null bs=1M count=1 > 1+0 records in > 1+0 records out > 1048576 bytes transferred in 0.190 secs (5506851 bytes/sec) > > Reading from the microSD: > # dd if=/dev/rsd1c of=/dev/null bs=1M count=1 > dd: /dev/rsd1c: Input/output error > 0+0 records in > 0+0 records out > 0 bytes transferred in 3.019 secs (0 bytes/sec) > > Reading from the eMMC again: > # dd if=/dev/rsd0c of=/dev/null bs=1M count=1 > dd: /dev/rsd0c: Input/output error > 0+0 records in > 0+0 records out > 0 bytes transferred in 0.004 secs (0 bytes/sec) > > At this point the system is unusable, and there's nothing else > interesting in dmesg.
Can reproduce this on the Lenovo stick, which is in many ways very similar to the 100s. So far I've not found a solution. Since the diff gives significant improvements and seems to be completely stable if I leave the SD card slot empty, I've committed it anyway. You may want to revert the changes to dev/acpi/sdhc_acpi.c for now if you intend to use the SD card slot on the 100s. Hopefully I'll figure out what the problem is soon. Otherwise I might selectively disable DMA support on this hardware.
