Re: [PATCH v2 2/2] scsi: sd: Rework asynchronous resume support

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hoi Bart,

On Mon, Aug 15, 2022 at 3:49 PM Bart Van Assche <bvanassche@acm.org> wrote:
> On 8/15/22 03:13, Geert Uytterhoeven wrote:
> > Showing all locks held in the system:
> > 1 lock held by rcu_tasks_kthre/10:
> >   #0: ffff800009575c38 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at:
> > rcu_tasks_one_gp+0x34/0x4c8
> > 4 locks held by kworker/0:10/104:
> >   #0: ffff0004c0008738 ((wq_completion)events){+.+.}-{0:0}, at:
> > process_one_work+0x1f4/0x6a0
> >   #1: ffff80000a90bde0
> > ((work_completion)(&ap->scsi_rescan_task)){+.+.}-{0:0}, at:
> > process_one_work+0x1f4/0x6a0
> >   #2: ffff0004c2b6bf60 (&ap->scsi_scan_mutex){+.+.}-{3:3}, at:
> > ata_scsi_dev_rescan+0x28/0x118
> >   #3: ffff0004c2902368 (&dev->mutex){....}-{3:3}, at:
> > scsi_rescan_device+0x28/0x78
> > 1 lock held by in:imklog/636:
> >   #0: ffff0004c5ee86e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x54/0x68
> > 1 lock held by hd/1013:
> >   #0: ffff0004c06388b8 (mapping.invalidate_lock#2){.+.+}-{3:3}, at:
> > page_cache_ra_unbounded+0x64/0x1a8
>
> Thank you for having shared this information. I will take a closer look
> and see what I can derive from the above information.
>
> > I've just tried with a USB storage device on the same platform,
> > and it can be read fine after s2idle.  So it looks like the issue
> > is related to SATA.
>
> Unfortunately the above does not learn us anything new. The code
> modified by commit 88f1669019bd ("scsi: sd: Rework asynchronous resume
> support") is only called if sdev->manage_start_stop != 1. Only the SATA
> code, the Firewire code and the manage_start_stop sysfs attribute store
> method set that member variable:
>
> $ git grep -nH 'manage_start_stop = '
> drivers/ata/libata-scsi.c:1083:         sdev->manage_start_stop = 1;
> drivers/firewire/sbp2.c:1521:           sdev->manage_start_stop = 1;
> drivers/scsi/sd.c:240:  sdp->manage_start_stop = v;
>
> Would it be possible to share the output of the command below? That
> should reveal which ATA driver is active on the test setup.
>
> find /sys -name proc_name | xargs grep -aH .

/sys/devices/platform/soc/ee300000.sata/ata1/host0/scsi_host/host0/proc_name:sata_rcar

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds