Messages in this thread Patch in this message | | | Date | Sat, 24 Sep 2022 23:29:34 +0200 | Subject | Re: [PATCH v4] usb: dwc3: Don't switch OTG -> peripheral if extcon is present | From | Ferry Toth <> |
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Hi,
One more test
Op 23-09-2022 om 20:23 schreef Andrey Smirnov: > On Fri, Sep 23, 2022 at 9:42 AM Andy Shevchenko > <andriy.shevchenko@intel.com> wrote: >> On Thu, Sep 22, 2022 at 04:32:55PM -0700, Andrey Smirnov wrote: >>> On Thu, Sep 22, 2022 at 3:23 AM Ferry Toth <fntoth@gmail.com> wrote: >>>> On 22-09-2022 12:08, Andy Shevchenko wrote: >>>> On Sun, Apr 03, 2022 at 09:49:07AM -0700, Andrey Smirnov wrote: >> FYI: For now I sent a revert, but if we got a solution quicker we always >> can choose the course of actions. >> > I think we have another problem. This patch happened in parallel to mine > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.0-rc6&id=ab7aa2866d295438dc60522f85c5421c6b4f1507 > > so my changes didn't have that fix in mind and I think your revert > will not preserve that fix. Can you update your revert to take care of > that too, please? > > I'm really confused how the above commit could be followed up by: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/usb/dwc3/drd.c?h=v6.0-rc6&id=0f01017191384e3962fa31520a9fd9846c3d352f > > the diffs in dwc3_drd_init seem contradictory > >>>> If the extcon device exists, get the mode from the extcon device. If >>>> the controller is DRD and the driver is unable to determine the mode, >>>> only then default the dr_mode to USB_DR_MODE_PERIPHERAL. >>>> >>>> According to Ferry (Cc'ed) this broke Intel Merrifield platform. Ferry, can you >>>> share bisect log? >>>> >>>> I can but not right now. But what I did was bisect between 5.18.0 (good) and 5.19.0 (bad) then when I got near the culprit (~20 remaining) based on the commit message I tried 0f01017191384e3962fa31520a9fd9846c3d352f "usb: dwc3: Don't switch OTG -> peripheral if extcon is present" (bad) and commit before that (good). >>>> >>>> The effect of the patch is that on Merrifield (I tested with Intel Edison Arduino board which has a HW switch to select between host and device mode) device mode works but in host mode USB is completely not working. >>>> >>>> Currently on host mode - when working - superfluous error messages from tusb1210 appear. When host mode is not working there are no tusb1210 messages in the logs / on the console at all. Seemingly tusb1210 is not probed, which points in the direction of a relation to extcon. >>>> >>>> Taking into account the late cycle, I would like to revert the change. And >>>> Ferry and I would help to test any other (non-regressive) approach). >>>> >>>> I have not yet tested if a simple revert fixes the problem but will tonight. >>>> >>>> >>>> I would be happy to test other approaches too. >>> >>> It's a bit hard for me to suggest an alternative approach without >>> knowing how things are breaking in this case. I'd love to order one of >>> those boards to repro and fix this on my end, but it looks like this >>> HW is EOLed and out of stock in most places. If you guys know how to >>> get my hands on those boards I'm all ears. >> There are still some second hand Intel Edison boards flying around >> (but maybe cost a bit more than expected) and there are also >> Dell Venue 7 3740 tablets based on the same platform/SoC. The latter >> option though requires more actions in order something to be boot >> there. >> > OK, I'll check e-bay just in case. > >> In any case, it's probably quicker to ask Ferry or me for testing. >> (Although currently I have no access to the board to test OTG, it's >> remote device which I can only power on and off and it has always >> be in host mode.) >> >>> Barring that, Ferry can you dig more into this failure? E.g. is it this hunk >>> >>> @@ -85,7 +86,7 @@ static int dwc3_get_dr_mode(struct dwc3 *dwc) >>> * mode. If the controller supports DRD but the dr_mode is not >>> * specified or set to OTG, then set the mode to peripheral. >>> */ >>> - if (mode == USB_DR_MODE_OTG && >>> + if (mode == USB_DR_MODE_OTG && !dwc->edev && >>> (!IS_ENABLED(CONFIG_USB_ROLE_SWITCH) || >>> !device_property_read_bool(dwc->dev, "usb-role-switch")) && >>> !DWC3_VER_IS_PRIOR(DWC3, 330A)) >>> @@ -1632,6 +1633,51 @@ static void dwc3_check_params(struct dwc3 *dwc) >>> } >>> } >>> >>> that's problematic or moving >> I think you wanted to revert only this line and test? > Yes. > >>> static int dwc3_probe(struct platform_device *pdev) >>> { >>> struct device *dev = &pdev->dev; >>> @@ -1744,6 +1790,13 @@ static int dwc3_probe(struct platform_device *pdev) >>> goto err2; >>> } >>> >>> + dwc->edev = dwc3_get_extcon(dwc); >>> + if (IS_ERR(dwc->edev)) { >>> + ret = PTR_ERR(dwc->edev); >>> + dev_err_probe(dwc->dev, ret, "failed to get extcon\n"); >>> + goto err3; >>> + } >>> + >>> ret = dwc3_get_dr_mode(dwc); >>> if (ret) >>> goto err3; >>> >>> to happen earlier?
I tried moving dwc3_get_extcon after dwc3_get_dr_mode like so::
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 8c8e32651473..3bf370def546 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1843,6 +1843,10 @@ static int dwc3_probe(struct platform_device *pdev) goto err2; }
+ ret = dwc3_get_dr_mode(dwc); + if (ret) + goto err3; + dwc->edev = dwc3_get_extcon(dwc); if (IS_ERR(dwc->edev)) { ret = PTR_ERR(dwc->edev); @@ -1850,10 +1854,6 @@ static int dwc3_probe(struct platform_device *pdev) goto err3; }
- ret = dwc3_get_dr_mode(dwc); - if (ret) - goto err3; - ret = dwc3_alloc_scratch_buffers(dwc); if (ret) goto err3; -- host mode still does not work (no change visible).
>> It is not always possible to have an extcon driver available, that's why in >> some cases the probe of it defers. I dunno how your patch supposed to work >> in that case. > I'm not sure I understand what you mean. AFAIU the logic is that if > the platform specifies the presence of extcon either via DT or, like > Merrifield, via and explicit "linux,extcon-name" device property in > the code then extcon is a mandatory component of the DRD stack and the > driver is expected to be present for the whole thing to work. I don't > think I really changed that logic with my patch, even after the revert > dwc3_get_extcon() will be called as a part of a probing codepath, so > if the a missing driver is causing a probe deferral it should still be > happening, unless I missed something. > >>> Does tracing the "mrfld_bcove_pwrsrc" driver (the >>> excton provider in this case AFIACT) show anything interesting? >> I believe there is nothing interesting. >> >> -- >> With Best Regards, >> Andy Shevchenko >> >>
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