Hi,

Oliver Neukum <oneu...@suse.com> writes:
> On Wed, 2016-04-13 at 08:42 +0300, Felipe Balbi wrote:
>> USB3 devices, because they are much newer, have much
>> less chance of having issues with larger transfers.
>> 
>> We still keep a limit because anything above 2048
>> sectors really rendered negligible speed
>> improvements, so we will simply ignore
>> that. Transferring 1MiB should already give us
>> pretty good performance.
>> 
>> Signed-off-by: Felipe Balbi <felipe.ba...@linux.intel.com>
>> ---
>>  drivers/usb/storage/scsiglue.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>> 
>> diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
>> index 9da1fb3d0ff4..2bb6a88858ea 100644
>> --- a/drivers/usb/storage/scsiglue.c
>> +++ b/drivers/usb/storage/scsiglue.c
>> @@ -127,6 +127,11 @@ static int slave_configure(struct scsi_device *sdev)
>>              if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
>>                      blk_queue_max_hw_sectors(sdev->request_queue,
>>                                            max_sectors);
>> +    } else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
>> +            /* USB3 devices will be limited to 2048 sectors. This gives us
>> +             * better throughput on most devices.
>> +             */
>> +            blk_queue_max_hw_sectors(sdev->request_queue, 2048);
>
> Should we really test for speed rather than USB version?

bcdUSB >= 0x0300 ? Sure, why not...

-- 
balbi

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