Sorry for the delayed response.... Vernon Sauder wrote: > I finally had some time to test this again. For refreshing, this is > testing an m25p80 MTD device on the PXA270 SPI bus. > > Good news and Bad news. Good news is that the error is gone with your > patch on 2.6.24.4. Bad news is that it there are still cases where the > kernel crashes or locks up using 2.6.27-rc8.
if you snapshotted 2.6.27-rc8, pxa2xx_spi would not have built properly. There was an error in a patch of mine that was fixed by a 2008-10-01 patch by Mike Rapoport, which would have been included in 2.6.27-rc9. You probably figured that out. > One time, this much of an error message got out before the kernel > completely locked up: > > [EMAIL PROTECTED] [~] # cat /tmp/k > /dev/mtd_spi > cat: Write Error: Bad address > [ 151.497694] ------------[ cut here ]------------ > [ 151.503356] WARNING: at kernel/mutex.c:135 > __mutex_lock_slowpath+0x9c/0x200() > [ 151.510452] Modules linked in: spidev > > And here is another dump that appeared after multiple writes: (Notice > first the failed writes. I don't know what is causing that. The HW setup > is slightly different.) [snip crash dump] I don't know if it could be related, but there is another thread "PXA270 SSP DMA Corruption" in which Scott Merritt reports trouble with the combination of spidev and pxa2xx_spi. He is also up-to-date with 2.6.27. He does not report kernel crashes, but simply corrupted data. I looked at spidev today (for the first time) and noticed that it uses the same buffer for rx and tx. That should be alright, except that I don't think that pxa2xx_spi handles that case correctly in DMA mode. pxa2xx_spi will try to dma_map_single() the same buffer twice, once in each direction. Are you using PIO or DMA mode? If DMA, can you try setting struct pxa2xx_spi_master.enable_dma = 0; If that works better, then maybe you have the same problem. > I wanted to send this so you know. There is the possibility that the > 2.6.27 I am using is not completely configured and/or patched. It was > based on Linus' git tree but I have not completed testing all my board > patches. This feature is not being requested any longer so I don't have > a lot of pressure to fix it right now. As I get closer to finishing the > project, I might need to resolve this. Maybe if you have some other issues, that would explain the difference in symptoms between your application and Merritt's. Alternatively, it could be different ways that messages are formatted by the chain of code that accesses MTD. Merritt is directly using the ioctl interface of spidev. -- Ned Forrester [EMAIL PROTECTED] Oceanographic Systems Lab 508-289-2226 Applied Ocean Physics and Engineering Dept. Woods Hole Oceanographic Institution Woods Hole, MA 02543, USA http://www.whoi.edu/sbl/liteSite.do?litesiteid=7212 http://www.whoi.edu/hpb/Site.do?id=1532 http://www.whoi.edu/page.do?pid=10079 ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ spi-devel-general mailing list spi-devel-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/spi-devel-general
