Re: [PATCH RESEND 0/3] scsi: fix internal write cache issue on usb hdd.
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On Sat, Jul 07, 2012 at 11:04:45PM -0400, Namjae Jeon wrote: > From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> > > The numbers of USB HDDs(All USB HDD I checked) does not respond > correctly to scsi mode sense command for retrieving the write cache > page status. Even though write cache is enabled by default, due to > scsi driver assume that cache is not enabled which in turn might lead > to loss of data since data still will be in cache. > This result that all filesystems is not stable on USB HDD when the > device is unplugged abruptly, even though these are having journaling > feature. Our first trying is that scsi driver send ATA command > (ATA Pass through, #85) to USB HDD after failure from normal routine to > know write cache enable. > We have known it is dangerous after testing several USB HDD. some of > HDD is stalled by this command(A-DATA HDD). So we tried to make the > patch James Bottomley's suggestion(usb quirk) on version 2 that add > product ID and verdor ID of USB HDD to USB quirk list after checking > write cache. > All filesystem will be stable on USB HDD registered in quirk list. > And it will be updated continuously. Now applied to the usb-next branch. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html