From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] usb: dwc3: omap: Fix imprecise external abort and oops on boot Date: Thu, 8 Dec 2016 07:37:34 -0800 Message-ID: <20161208153734.GF4264@atomide.com> References: <20161208032108.21962-1-tony@atomide.com> <87lgvqkb6f.fsf@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Return-path: Content-Disposition: inline In-Reply-To: <87lgvqkb6f.fsf-VuQAYsv1563Yd54FQh9/CA@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Felipe Balbi Cc: Greg Kroah-Hartman , Grygorii Strashko , Roger Quadros , Sekhar Nori , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-omap@vger.kernel.org * Felipe Balbi [161208 01:45]: > > Hi, > > Tony Lindgren writes: > > Somehow starting with v4.9-rc7 there have been imprecise > > There's nothing touching dwc3 since v4.9-rc5. Right, nothing obvious has changed. I think it's just a slight timing change in the code that started triggering it. > > external aborts on omap5-uevm dwc3 controller. I have not been > > able to bisect what exactly triggered this as it does not always > > happen. It seems that something changed with probing that > > now exposes the issue: > > > > Unhandled fault: imprecise external abort (0x1406) at 0x00000000 > > hmmm, clock disabled... dwc3-omap shouldn't have pm runtime at all. It does for the interconnect target module clkctrl register via PM runtime. That's the "usb_otg_ss" module. > > ... > > PC is at dwc3_omap_interrupt_thread+0x20/0x80 > > LR is at irq_thread_fn+0x1c/0x54 > > ... > > [] (dwc3_omap_interrupt_thread) from [] > > (irq_thread_fn+0x1c/0x54) > > [] (irq_thread_fn) from [] (irq_thread+0x12c/0x1f0) > > [] (irq_thread) from [] (kthread+0xdc/0xf4) > > [] (kthread) from [] (ret_from_fork+0x14/0x3c) > > ... > > > > Unable to handle kernel paging request at virtual address ffffffec > > ... > > Internal error: Oops: 37 [#2] SMP ARM > > PC is at kthread_data+0x4/0xc > > LR is at irq_thread_dtor+0x28/0xd0 > > ... > > [] (kthread_data) from [] (irq_thread_dtor+0x28/0xd0) > > [] (irq_thread_dtor) from [] (task_work_run+0xb8/0xdc) > > [] (task_work_run) from [] (do_exit+0x314/0xa20) > > [] (do_exit) from [] (die+0x410/0x474) > > [] (die) from [] (do_DataAbort+0xb4/0xb8) > > [] (do_DataAbort) from [] (__dabt_svc+0x58/0x80) > > Exception stack(0xee777ec8 to 0xee777f10) > > 7ec0: 0000014d ee6e6f10 00000034 fc020034 ee6e6f10 ee1eec00 > > 7ee0: 00000000 00000000 ee6ec640 c038a4bc 00000000 00000000 00000000 ee777f18 > > 7f00: c038a4d8 c0989fa8 60000013 ffffffff > > [] (__dabt_svc) from [] (dwc3_omap_interrupt_thread+0x20/0x80) > > [] (dwc3_omap_interrupt_thread) from [] (irq_thread_fn+0x1c/0x54) > > [] (irq_thread_fn) from [] (irq_thread+0x12c/0x1f0) > > [] (irq_thread) from [] (kthread+0xdc/0xf4) > > [] (kthread) from [] (ret_from_fork+0x14/0x3c) > > > > Fix the issue by making sure the dwc3 interrupts are disabled > > before we call devm_request_threaded_irq(). > > that should already be the case. Are you sure that register isn't zero > in probe? Looks like irq0_status = 0 and irqmisc_status = 0x2121. Also just clearing irqmisc with dwc3_omap_write_irqmisc_clr(omap, 0xffffffff) stops the issue from happening. There is some deferred probing happening but irqmisc is always 0x2121. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html