Hi, On 09/09/2014 05:27 PM, Christoph Hellwig wrote: > On Tue, Sep 09, 2014 at 11:15:24AM +0200, Hans de Goede wrote: >> Taking the uas.c file from 3.17, and building it for 3.16 restores >> the use of tcq (debugged by adding a printk blk_rq_tagged + request->tag). >> >> So either uas is doing something wrong which happened to work in >> 3.16, or something has broken in 3.17. >> >> I've already added debug printk-s of scsi_device->tagged_supported, >> queue_depth, ordered_tags and simple_tags and those all look good >> (1, 29, 1, 1). >> >> I've also tried setting disable_blk_mq and that does not help. >> >> Any hints to help debugging this further (other then a bisect) are >> appreciated. If no-one has any smart ideas I guess I'll end up doing >> a full bisect. > > scsi-mq isn't enabled by default, so setting disable_blk_mq should > indeed not make a difference. > > One interesting thing with uas is that it uses scsi_init_shared_tag_map, > which only few drivers do. > > Can you apply a debug patch like the one below and see if that helps to > poinpoint down the issue? I've applied the patch, this results in the following new dmesg output when using uas: [ 120.602632] initialized host-wide tag map! Thank you for looking into this. Regards, Hans -- 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
