On 05/01/18 02:09, Troy Kisky wrote:
> On 12/29/2017 3:34 AM, Marc Zyngier wrote:
>> On Wed, 27 Dec 2017 20:37:07 +0000,
>> Troy Kisky wrote:
>>>
>>> On 12/27/2017 2:37 AM, Marc Zyngier wrote:
>>>> On Tue, 26 Dec 2017 21:57:58 +0000,
>>>> Troy Kisky wrote:
>>>>>
>>>>> On 12/26/2017 1:52 PM, Troy Kisky wrote:
>>>>>> On 12/25/2017 2:10 AM, Marc Zyngier wrote:
>>>>>>> On Sun, 24 Dec 2017 23:01:33 +0000,
>>>>>>> Troy Kisky wrote:
>>>>>>>>
>>>>>>>> commit 8466489ef5ba48272ba4fa4ea9f8f403306de4c7
>>>>>>>> Author: Marc Zyngier <marc.zyngier@xxxxxxx>
>>>>>>>> Date: Tue Aug 1 20:11:08 2017 -0500
>>>>>>>>
>>>>>>>> xhci: Reset Renesas uPD72020x USB controller for 32-bit DMA issue
>>>>>>>> ...
>>>>>>>> ...
>>>>>>>> ...
>>>>>>>> --- a/drivers/usb/host/xhci-pci.c
>>>>>>>> +++ b/drivers/usb/host/xhci-pci.c
>>>>>>>> @@ -284,6 +284,13 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
>>>>>>>>
>>>>>>>> driver = (struct hc_driver *)id->driver_data;
>>>>>>>>
>>>>>>>> + /* For some HW implementation, a XHCI reset is just not enough... */
>>>>>>>> + if (usb_xhci_needs_pci_reset(dev)) {
>>>>>>>> + dev_info(&dev->dev, "Resetting\n");
>>>>>>>> + if (pci_reset_function_locked(dev))
>>>>>>>> + dev_warn(&dev->dev, "Reset failed");
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> ________
>>>>>>>>
>>>>>>>>
>>>>>>>> This pci_reset_function_locked call, causes my i.mx6qp processor to
>>>>>>>> hang. It no longer responds to the MAGIC_SYSRQ key (break on serial
>>>>>>>> port).
>>>>>>>>
>>>>>>>>
>>>>>>>> If I comment it out, things return to normal when testing on
>>>>>>>> Linux-next (20171222).
>>>>>>>>
>>>>>>>> If you need more info, let me know.
>>>>>>>
>>>>>>> Well, for a start:
>>>>>>>
>>>>>>> - Does it fail with 4.13 or 4.14 too?
>>>>>>
>>>>>> v4.13-rc4 - good
>>>>>> v4.13-rc5 - fail
>>>>>> v4.13 - fail
>>>>>> v4.14 - fail
>>>>>>
>>>>>>
>>>>>>
>>>>>>> - Can you work out where it is locking up exactly (going slightly
>>>>>>> deeper than the pci_reset_function_locked() call)?
>>>>>>
>>>>>> With this patch
>>>>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>>>>>> index 05104bd2b611..8782945a9f70 100644
>>>>>> --- a/drivers/usb/host/xhci.c
>>>>>> +++ b/drivers/usb/host/xhci.c
>>>>>> @@ -4808,8 +4808,10 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
>>>>>>
>>>>>> mutex_init(&xhci->mutex);
>>>>>> xhci->cap_regs = hcd->regs;
>>>>>> + pr_err("%s: 1\n", __func__);
>>>>>> xhci->op_regs = hcd->regs +
>>>>>> HC_LENGTH(readl(&xhci->cap_regs->hc_capbase));
>>>>>> + pr_err("%s: 2\n", __func__);
>>>>>> xhci->run_regs = hcd->regs +
>>>>>> (readl(&xhci->cap_regs->run_regs_off) & RTSOFF_MASK);
>>>>>> /* Cache read-only capability registers */
>>>>>> _____________________
>>>>>>
>>>>>> The last thing printed is
>>>>>> [ OK ] Reached target System Initialization.
>>>>>> [ OK ] Listening on D-Bus System Message Bus Socket.
>>>>>> [ OK ] Reached target Sockets.
>>>>>> [ OK ] Started Daily Cleanup of Temporary Directories.
>>>>>> [ 15.770319] xhci_gen_setup: 1
>>>>
>>>> OK, so it looks like the CPU is blocked reading from the
>>>> device. Almost feels like the device is not clocked (that's about the
>>>> only reason why the CPU would be stuck on such a read).
>>>>
>>>>>>
>>>>>>
>>>>>>> - Do you get the symptom at boot time?
>>>>>>
>>>>>> Boot
>>>>>>
>>>>>>> On resume? Is the USB driver
>>>>>>> compiled as a module or built-in?
>>>>>>
>>>>>> INSTALL drivers/usb/host/xhci-hcd.ko
>>>>>> INSTALL drivers/usb/host/xhci-pci.ko
>>>>>> INSTALL drivers/usb/host/xhci-renesas.ko
>>>>>>
>>>>>>> - What is your exact platform (something a bit more precise than just
>>>>>>> i.MX6...)?
>>>>>>
>>>>>> It is a custom board not in mainline. It does need to load firmware.
>>>>>>
>>>>>> I tried moving pci_reset_function_locked before renesas_check_if_fw_dl_is_needed
>>>>>> but that did not help.
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Which I should say I also have this patch
>>>>>
>>>>>
>>>>> commit 01ac5cfd811088b5fe8c97f28f96086e30393c66
>>>>> Author: Christian Lamparter <chunkeey@xxxxxxxxx>
>>>>> Date: Wed Jun 8 00:14:57 2016 +0200
>>>>>
>>>>> usb: xhci: handle uPD720201 and uPD720202 w/o ROM
>>>>>
>>>>> This patch adds a firmware check for the uPD720201K8-711-BAC-A
>>>>> and uPD720202K8-711-BAA-A variant. Both of these chips are listed
>>>>> in Renesas' R19UH0078EJ0500 Rev.5.00 "User's Manual: Hardware" as
>>>>> devices which need a firmware in order to work as they do not have
>>>>> support to load the firmware from an external ROM.
>>>>>
>>>>> __________
>>>>>
>>>>> Sorry for not saying earlier.
>>>>
>>>> That's a very interesting piece of information. Looking at that
>>>> patch[1], it doesn't provide any FW loader, and simply detects whether
>>>> the firmware is correctly present and running.
>>>>
>>>> What is probably happening is that your bootloader loads the XHCI
>>>> firmware, the driver resets the XHCI device, and the firmware is
>>>> lost. Assuming my hunch is right, what would be required here is for
>>>> the firmware to be loaded after the reset, but that'd require writing
>>>> a firmware loader for xhci-pci (probably not a huge undertaking)
>>>>
>>>> Could you please investigate whether my hunch is correct or not?
>>>>
>>>> Thanks,
>>>>
>>>> M.
>>>>
>>>> [1]: https://patchwork.kernel.org/patch/9162693/
>>>>
>>>
>>> Hi Marc
>>>
>>>
>>> It already had a firmware downloader, and I tried reset both before and after that. No change.
>>>
>>>
>>> So, now I've tried the same thing with 0 patches to linux-next. A nitrogen6_max board
>>> with a Renesas USB3.0 PCIe card that has a firmware ROM, and so does not need the extra patch.
>>>
>>> 01:00.0 USB controller: Renesas Technology Corp. uPD720201 USB 3.0 Host Controller (rev 03)
>>>
>>> It behaves identically to the other board. So, the firmware issue is a red herring.
>>>
>>> [ OK ] Found device /dev/ttymxc0.
>>> [ OK ] Found device /dev/ttymxc1.
>>> [ 11.916718] xhci_gen_setup: 1
>>
>> Fair enough. Can you try reseting another endpoint? I'm trying to work
>> out whether this is an iMX6 issue or something else. You should be
>> able to unload/unbind the driver, reset the device by writing to
>> /sys/bus/pci/devices/0000:01:00.0/reset (for example), and reload the driver.
>>
>> Thanks,
>>
>> M.
>>
>
> That makes it hang as well...
>
>
> root@nitrogen:/sys/bus/pci/devices/0000:01:00.0# echo 1 >reset
> root@nitrogen:/sys/bus/pci/devices/0000:01:00.0#
> root@nitrogen:/sys/bus/pci/devices/0000:01:00.0#
> root@nitrogen:/sys/bus/pci/devices/0000:01:00.0# modprobe xhci_pci
> [ 236.369271] xhci_hcd 0000:01:00.0: Resetting
> [ 236.374916] xhci_hcd 0000:01:00.0: xHCI Host Controller
> [ 236.380444] xhci_hcd 0000:01:00.0: new USB bus registered, assigned bus number 2
But that's the same device right? Sorry if I was unclear, but I was
hoping you could try with another device altogether (an Ethernet card,
for example).
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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