>>>> >>>> I tested with lot of values. I'm not totally sure but it looks the 31 >>>> is max number where it is still stable to create an ext4 filesystem. >>> >>> Thanks, that is good to know. Can you try the following patch instead >>> of changing can_queue ? : >>> >>> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c >>> index 511b229..6cdc1b9 100644 >>> --- a/drivers/usb/storage/uas.c >>> +++ b/drivers/usb/storage/uas.c >>> @@ -1033,6 +1033,7 @@ static int uas_configure_endpoints(struct uas_dev_info *devinfo) >>> 3, 256, GFP_NOIO); >>> if (devinfo->qdepth < 0) >>> return devinfo->qdepth; >>> + devinfo->qdepth = 32; >>> devinfo->use_streams = 1; >>> } >>> >>> >>> Note that the 32 rather then 31 is on purpose. There is 1 stream reserved >>> for non tagged commands, so under normal use a can_queue of 31 will cause >>> streams 2-32 to be used (stream addresses start at 1 not 0). >>> >>> And can you please also do (with the device plugged in): >>> >>> sudo lsusb -v &> lsusb.log and attach lsusb.log to your next mail? >>> >>> Then assuming my alternative patch works, I'll write a patch to allow >>> overriding max qdepth from a quirk + a quirk for your enclosure. >> >> Thank you, I will try it tonight. >> I've already sent the output of lsusb in my first email: >> https://www.mail-archive.com/linux-usb@xxxxxxxxxxxxxxx/msg46005.html > > Ah, I forgot about that one. That one however seems to be with the > device plugged into a usb-2 port, do you have a machine with a usb-3 > port and if so can you do the lsusb with the device plugged into > a usb-3 port (*) ? > > This also raises the question if you've been doing your testing where > using 31 seems to fix things with the device plugged into a usb-2 or a > usb-3 port ? > > Note that my patch won't do anything for the device plugged into > an usb-2 port, in that case you need to change the qdepth = 256 a > few lines higher to qdepth = 32. > > If you've access to both usb-2 and usb-3 ports, it would be good if you > could test with both, and let us know if you you need qdepth = 32 to fix > things in both cases. > > I've just re-read the uas spec and it does not say anything about how to > determine the uas bridge's max qdepth when running in usb-2, so maybe > rather then making this a quirk we need to play it safe and change > the qdepth = 256 to qdepth = 32 unconditionally. In usb-3 mode most > bridges don't seem to support more then 16 or 32 as qdepth, chances > are that for some implementations the same applies to usb-2 mode. > > Given the relative low speed of the usb-2 bus a qdepth of 32 or even > 16 should be more then enough to get most of the benefits of tcq. > > Regards, > > Hans > > > *) usb devices return different descriptors at different speeds All tests were on usb2. I don't have usb3 ports but I will try that at weekend. I'm curious now, am I the first one who has ever tested uas on usb2? Br, Laszlo -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
