Hi, 2010/1/20 Robert Hancock <hancockrwd@xxxxxxxxx>: > On 01/19/2010 09:30 PM, Tejun Heo wrote: >> >> Hello, >> >> On 01/17/2010 08:56 AM, Bart Hartgers wrote: >>> >>> When writing a disc on certain lite-on dvd-writers (also rebadged as >>> optiarc/LG/...) connected to a vt6420, the ATAPI CDB ends up in the >>> datastream and on the disc, causing silent corruption. Delaying >>> between sending the CDB and starting DMA seems to prevent this. >>> >>> I do not know if there are burners that do not suffer from this, but >>> the patch should be safe for those as well. >>> >>> There are many reports of this issue, but AFAICT no solution was >>> found before. For example: >>> http://lkml.indiana.edu/hypermail/linux/kernel/0802.3/0561.html >>> >>> Signed-off-by: Bart Hartgers<bart.hartgers@xxxxxxxxx> >> >> Ah... you found solution for this? That's great. This is one of the >> three problems that have been lingering for years - the other two >> being pata_ali ATAPI DMA problem and sata_sil data corruption problem. >> I'll be ecstatic if this fix works. Just one thing, I don't think >> we'll need a warning message there. It's useful during development >> but it doesn't really provide any useful information afterwards. > > Another tiny nitpick about the patch, the unlikely() around the > DMA_TO_DEVICE check probably shouldn't be there - unlikely() is for things > that will always be either highly unlikely or a slow path, neither of which > really apply. > Well, the ata_sff_pause actually does a ndelay(400), and with today's processors that would be a 'slow path', right? Groeten, Bart >> >> Digging up the mailing list and cc'ing people who have reported this >> problem. If you still have the affected systems, can you guys please >> test the patch in the following message and see whether it fixes the >> problem? >> >> http://article.gmane.org/gmane.linux.kernel/939112/raw >> >> Thanks a lot. :-) >> > > -- Bart Hartgers - New e-mail: bart.hartgers@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
