Hi Greg. Would you check this patch-set ? Thanks. 2012/6/14, Namjae Jeon <linkinjeon@xxxxxxxxx>: > 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, #58) 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'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. > > scsi: set to WCE if usb cache quirk is present. > usb: storage: add support for write cache quirk on usb hdd. > usb: storage: update usb devices for write cache quirk in quirk. > > drivers/scsi/sd.c | 9 +++++++-- > include/scsi/scsi_device.h | 1 + > drivers/usb/storage/scsiglue.c | 5 +++++ > drivers/usb/storage/usb.c | 5 ++++- > include/linux/usb_usual.h | 4 +++- > drivers/usb/storage/unusual_devs.h | 24 ++++++++++++++++++++++++ > Documentation/kernel-parameters.txt | 2 ++ > 7 files changed, 46 insertions(+), 4 deletions(-) > -- > 1.7.9.5 > > -- 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
