| Message ID | cover.1599549364.git.mchehab+huawei@kernel.org |
|---|---|
| Headers | show |
| Series | Add a quirk for dwc3 driver, requred for Hikey 970 USB to work | expand |
Em Tue, 15 Sep 2020 10:38:14 -0600 Rob Herring <robh@kernel.org> escreveu: > On Tue, Sep 08, 2020 at 09:20:57AM +0200, Mauro Carvalho Chehab wrote: > > At Hikey 970, setting the SPLIT disable at the General > > User Register 3 is required. > > > > Without that, the URBs generated by the usbhid driver > > return -EPROTO errors. That causes the code at > > hid-core.c to call hid_io_error(), which schedules > > a reset_work, causing a call to hid_reset(). > > > > In turn, the code there will call: > > > > usb_queue_reset_device(usbhid->intf); > > > > The net result is that the input devices won't work, and > > will be reset on every 0.5 seconds: > > > > [ 33.122384] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > [ 33.378220] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > [ 33.698394] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > [ 34.882365] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > [ 35.138217] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > [ 35.458617] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > [ 36.642392] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > [ 36.898207] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > [ 37.218598] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > [ 38.402368] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > [ 38.658174] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > [ 38.978594] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > [ 40.162361] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > [ 40.418148] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > ... > > [ 397.698132] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> > > --- > > Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > > index d03edf9d3935..1aae2b6160c1 100644 > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > > @@ -78,6 +78,9 @@ Optional properties: > > park mode are disabled. > > - snps,dis_metastability_quirk: when set, disable metastability workaround. > > CAUTION: use only if you are absolutely sure of it. > > + - snps,dis-split-quirk: when set, change the way URBs are handled by the > > + driver. Needed to avoid -EPROTO errors with usbhid > > + on some devices (Hikey 970). > > Can't this be implied by the compatible string? Yes we have quirk > properties already, but the problem with them is you can't address them > without a DT change. Short answer: While technically doable, I don't think that this would be a good idea. - Long answer: The first thing is related to the compatible namespace: should such quirk be added at SoC level or at board level? I don't know if the need to disable split mode came from a different dwc3 variant used by the Kirin 970 SoC, or if this is due to the way USB is wired at the Hikey 970 board. Right now, I'm assuming the latter, but Felipe suggested that this might be due to a different version of the IP. Currently, we have no means to check. So, I'm placing all Hikey 970 specific quirks under the board-specific part, e. g., at: arch/arm64/boot/dts/hisilicon/hi3670-hikey970.dts This sounds more flexible, as, if some different hardware based on the same chipset reaches upstream, it could use a different set of quirks, if needed. However, if we decide to bind quirks with compatible strings, we need to know if we would create a board-specific compatible or just SoC-specific ones. - Another possibility would be to add generic compatible bindings for each quirk featureset. Right now the dwc3 core driver accepts only two compatible strings: .compatible = "snps,dwc3" .compatible = "synopsys,dwc3" And both are equivalent. No quirks are added there via compatible strings. Ok, we might start adding different compatible strings for different sets of quirks, like: .compatible = "snps,dwc3-splitdisable" but, this sounds really ugly, specially when multiple quirks would be required. We might also deprecate the usage of "snps,dwc3"/"synopsys,dwc3", in favor of SoC-specific and board-specific compatible strings, but that would add a long list of boards there, with lots of code to set quirks. IMHO, it is a lot nicer to rely on DT to enable or disable those SoC and board-specific optional features of the Designware IP. - In the specific case of Hikey 970, there are two other alternatives: 1) we ended needing to create a new compatible for the Kirin 970 SoC, for it to be probed via this driver: drivers/usb/dwc3/dwc3-of-simple.c as, otherwise an async ARM error happens, making the SoC to crash. All dwc3-of-simple driver does is to use a different code for initializing the clocks. However, dwc3-of-simple driver is completely independent from dwc3: it doesn't pass platform data to the main dwc3 driver. So, it doesn't propagate any quirk to the main driver. One possible hack would be to make dwc3 driver to also accept platform data, using it as an interface for the dwc3-of-simple to pass quirks. If we go on that direction, we could also remove all other quirks from Kirin 970 dwc3, coding them inside the driver, instead of using DT, e. g. the driver would do something like: if (of_device_is_compatible(np, "hisilicon,hi3670-dwc3")) { cfg->dis_split_quirk = true; cfg->foo = true; cfg->bar = true; ... } such change would require a re-design at the logic around dwc3_get_properties(), as the driver should start accepting quirks either from platform_data or from DT (or both?). 2) Because this specific device uses the dwc3-of-simple driver, the actual DT binding is: usb3: hisi_dwc3 { compatible = "hisilicon,hi3670-dwc3"; ... dwc3: dwc3@ff100000 { compatible = "snps,dwc3"; ... }; }; For boards that use dwc3-of-simple drivers, we could add a hack at the dwc3 core that would seek for the parent's device's compatible string with something like (not tested): if (of_device_is_compatible(pdev->parent->dev.of_node, "hisilicon,hi3670-dwc3")) dwc->dis_split_quirk = true; It should be noticed that both platform_data and pdev->parent alternatives will only work for boards using dwc3-of-simple driver. This could limit this quirk usage on future devices. - IMO, adding a new quirk is cleaner, and adopts the same solution that it is currently used by other drivers with Designware IP. Thanks, Mauro
On Thu, Sep 17, 2020 at 1:18 AM Mauro Carvalho Chehab <mchehab+huawei@kernel.org> wrote: > > Em Tue, 15 Sep 2020 10:38:14 -0600 > Rob Herring <robh@kernel.org> escreveu: > > > On Tue, Sep 08, 2020 at 09:20:57AM +0200, Mauro Carvalho Chehab wrote: > > > At Hikey 970, setting the SPLIT disable at the General > > > User Register 3 is required. > > > > > > Without that, the URBs generated by the usbhid driver > > > return -EPROTO errors. That causes the code at > > > hid-core.c to call hid_io_error(), which schedules > > > a reset_work, causing a call to hid_reset(). > > > > > > In turn, the code there will call: > > > > > > usb_queue_reset_device(usbhid->intf); > > > > > > The net result is that the input devices won't work, and > > > will be reset on every 0.5 seconds: > > > > > > [ 33.122384] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > [ 33.378220] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > [ 33.698394] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > [ 34.882365] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > [ 35.138217] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > [ 35.458617] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > [ 36.642392] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > [ 36.898207] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > [ 37.218598] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > [ 38.402368] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > [ 38.658174] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > [ 38.978594] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > [ 40.162361] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > [ 40.418148] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > ... > > > [ 397.698132] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> > > > --- > > > Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > > > index d03edf9d3935..1aae2b6160c1 100644 > > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > > > @@ -78,6 +78,9 @@ Optional properties: > > > park mode are disabled. > > > - snps,dis_metastability_quirk: when set, disable metastability workaround. > > > CAUTION: use only if you are absolutely sure of it. > > > + - snps,dis-split-quirk: when set, change the way URBs are handled by the > > > + driver. Needed to avoid -EPROTO errors with usbhid > > > + on some devices (Hikey 970). > > > > Can't this be implied by the compatible string? Yes we have quirk > > properties already, but the problem with them is you can't address them > > without a DT change. > > Short answer: > > While technically doable, I don't think that this would be a good idea. > > - > > Long answer: > > The first thing is related to the compatible namespace: should such > quirk be added at SoC level or at board level? > > I don't know if the need to disable split mode came from a different > dwc3 variant used by the Kirin 970 SoC, or if this is due to the way > USB is wired at the Hikey 970 board. If board specific, then I agree that a separate property makes sense. This doesn't really sound board specific though. > Right now, I'm assuming the latter, but Felipe suggested that this > might be due to a different version of the IP. Currently, we have > no means to check. > > So, I'm placing all Hikey 970 specific quirks under the board-specific > part, e. g., at: > > arch/arm64/boot/dts/hisilicon/hi3670-hikey970.dts > > This sounds more flexible, as, if some different hardware based on > the same chipset reaches upstream, it could use a different set of > quirks, if needed. > > However, if we decide to bind quirks with compatible strings, > we need to know if we would create a board-specific compatible > or just SoC-specific ones. > > - > > Another possibility would be to add generic compatible bindings > for each quirk featureset. Right now the dwc3 core driver accepts > only two compatible strings: > > .compatible = "snps,dwc3" > .compatible = "synopsys,dwc3" Yeah, the binding for DWC3 is odd. > And both are equivalent. No quirks are added there via compatible > strings. > > Ok, we might start adding different compatible strings for different > sets of quirks, like: > > .compatible = "snps,dwc3-splitdisable" Um, no. > > but, this sounds really ugly, specially when multiple quirks > would be required. > > We might also deprecate the usage of "snps,dwc3"/"synopsys,dwc3", > in favor of SoC-specific and board-specific compatible strings, > but that would add a long list of boards there, with lots of code > to set quirks. IMHO, it is a lot nicer to rely on DT to enable > or disable those SoC and board-specific optional features of the > Designware IP. > > - > > In the specific case of Hikey 970, there are two other > alternatives: > > 1) we ended needing to create a new compatible for the Kirin 970 > SoC, for it to be probed via this driver: > > drivers/usb/dwc3/dwc3-of-simple.c > > as, otherwise an async ARM error happens, making the SoC to > crash. All dwc3-of-simple driver does is to use a different > code for initializing the clocks. > > However, dwc3-of-simple driver is completely independent from > dwc3: it doesn't pass platform data to the main dwc3 driver. > So, it doesn't propagate any quirk to the main driver. > > One possible hack would be to make dwc3 driver to also > accept platform data, using it as an interface for the > dwc3-of-simple to pass quirks. > > If we go on that direction, we could also remove all other > quirks from Kirin 970 dwc3, coding them inside the driver, > instead of using DT, e. g. the driver would do something like: > > if (of_device_is_compatible(np, > "hisilicon,hi3670-dwc3")) { > cfg->dis_split_quirk = true; > cfg->foo = true; > cfg->bar = true; Normally, this would all be driver match data. > ... > > } > > such change would require a re-design at the logic around > dwc3_get_properties(), as the driver should start accepting > quirks either from platform_data or from DT (or both?). > > 2) Because this specific device uses the dwc3-of-simple driver, > the actual DT binding is: > > usb3: hisi_dwc3 { > compatible = "hisilicon,hi3670-dwc3"; > ... > dwc3: dwc3@ff100000 { > compatible = "snps,dwc3"; > ... > }; > }; This parent child split should never have happened for the cases that don't have 'wrapper registers'. We should have had on node here with just: compatible = "hisilicon,hi3670-dwc3", "snps,dwc3"; > For boards that use dwc3-of-simple drivers, we could add a hack > at the dwc3 core that would seek for the parent's device's > compatible string with something like (not tested): > > if (of_device_is_compatible(pdev->parent->dev.of_node, > "hisilicon,hi3670-dwc3")) > dwc->dis_split_quirk = true; This is what I'd do. You could have a match table instead as that would scale better. > It should be noticed that both platform_data and pdev->parent > alternatives will only work for boards using dwc3-of-simple driver. > This could limit this quirk usage on future devices. > > - > > IMO, adding a new quirk is cleaner, and adopts the same solution > that it is currently used by other drivers with Designware IP. We already have a bunch of quirk properties. What's one more, sigh. So if that's what you want, fine. Rob
Em Thu, 17 Sep 2020 08:47:48 -0600 Rob Herring <robh@kernel.org> escreveu: > On Thu, Sep 17, 2020 at 1:18 AM Mauro Carvalho Chehab > <mchehab+huawei@kernel.org> wrote: > > > > Em Tue, 15 Sep 2020 10:38:14 -0600 > > Rob Herring <robh@kernel.org> escreveu: > > > > > On Tue, Sep 08, 2020 at 09:20:57AM +0200, Mauro Carvalho Chehab wrote: > > > > At Hikey 970, setting the SPLIT disable at the General > > > > User Register 3 is required. > > > > > > > > Without that, the URBs generated by the usbhid driver > > > > return -EPROTO errors. That causes the code at > > > > hid-core.c to call hid_io_error(), which schedules > > > > a reset_work, causing a call to hid_reset(). > > > > > > > > In turn, the code there will call: > > > > > > > > usb_queue_reset_device(usbhid->intf); > > > > > > > > The net result is that the input devices won't work, and > > > > will be reset on every 0.5 seconds: > > > > > > > > [ 33.122384] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > > [ 33.378220] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > [ 33.698394] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > > [ 34.882365] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > > [ 35.138217] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > [ 35.458617] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > > [ 36.642392] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > > [ 36.898207] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > [ 37.218598] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > > [ 38.402368] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > > [ 38.658174] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > [ 38.978594] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0000 > > > > [ 40.162361] hub 1-1:1.0: state 7 ports 4 chg 0000 evt 0002 > > > > [ 40.418148] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > ... > > > > [ 397.698132] usb 1-1.1: reset low-speed USB device number 3 using xhci-hcd > > > > > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> > > > > --- > > > > Documentation/devicetree/bindings/usb/dwc3.txt | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt > > > > index d03edf9d3935..1aae2b6160c1 100644 > > > > --- a/Documentation/devicetree/bindings/usb/dwc3.txt > > > > +++ b/Documentation/devicetree/bindings/usb/dwc3.txt > > > > @@ -78,6 +78,9 @@ Optional properties: > > > > park mode are disabled. > > > > - snps,dis_metastability_quirk: when set, disable metastability workaround. > > > > CAUTION: use only if you are absolutely sure of it. > > > > + - snps,dis-split-quirk: when set, change the way URBs are handled by the > > > > + driver. Needed to avoid -EPROTO errors with usbhid > > > > + on some devices (Hikey 970). > > > > > > Can't this be implied by the compatible string? Yes we have quirk > > > properties already, but the problem with them is you can't address them > > > without a DT change. > > > > Short answer: > > > > While technically doable, I don't think that this would be a good idea. > > > > - > > > > Long answer: > > > > The first thing is related to the compatible namespace: should such > > quirk be added at SoC level or at board level? > > > > I don't know if the need to disable split mode came from a different > > dwc3 variant used by the Kirin 970 SoC, or if this is due to the way > > USB is wired at the Hikey 970 board. > > If board specific, then I agree that a separate property makes sense. > This doesn't really sound board specific though. Yeah, I agree that the higher chance is that this would be SoC specific, but I can't discard being board-specific either, as, on this board, all the output ports are all connected via an USB GPIO hub provided on a different chipset. Funny enough, setting this is only required for HID. The USB ports work fine either with split mode enabled or disabled for USB sticks. So, I guess this affects only INT (and maybe ISOC) URB transfers. So I wouldn't doubt that such quirk would be required due to some limitation at the USB GPIO hub. > > 2) Because this specific device uses the dwc3-of-simple driver, > > the actual DT binding is: > > > > usb3: hisi_dwc3 { > > compatible = "hisilicon,hi3670-dwc3"; > > ... > > dwc3: dwc3@ff100000 { > > compatible = "snps,dwc3"; > > ... > > }; > > }; > > This parent child split should never have happened for the cases that > don't have 'wrapper registers'. We should have had on node here with > just: > > compatible = "hisilicon,hi3670-dwc3", "snps,dwc3"; I tried to do that, but the ARM CPU panics: https://lore.kernel.org/linux-usb/731e13f9fbba3a81bedb39f1c1deaf41200acd0c.1599559004.git.mchehab+huawei@kernel.org/ From my tests, it sounds that this is due to some (minor) differences on how the power clocks are enabled/suspended when using dwc3-of-simple as the parent node. It sounds that, if the PM clocks are not stable yet by the time dwc3 tries to initialize, the CPU crashes. > > For boards that use dwc3-of-simple drivers, we could add a hack > > at the dwc3 core that would seek for the parent's device's > > compatible string with something like (not tested): > > > > if (of_device_is_compatible(pdev->parent->dev.of_node, > > "hisilicon,hi3670-dwc3")) > > dwc->dis_split_quirk = true; > > This is what I'd do. You could have a match table instead as that > would scale better. Not sure if a match table would work here, because we need to enforce that the parent node will be called before dwc3, as otherwise the panic() will occur. > > It should be noticed that both platform_data and pdev->parent > > alternatives will only work for boards using dwc3-of-simple driver. > > This could limit this quirk usage on future devices. > > > > - > > > > IMO, adding a new quirk is cleaner, and adopts the same solution > > that it is currently used by other drivers with Designware IP. > > We already have a bunch of quirk properties. What's one more, sigh. So > if that's what you want, fine. Ok, thanks! Thanks, Mauro
Ping. Felipe, Em Thu, 17 Sep 2020 08:47:48 -0600 Rob Herring <robh@kernel.org> escreveu: > On Thu, Sep 17, 2020 at 1:18 AM Mauro Carvalho Chehab > <mchehab+huawei@kernel.org> wrote: > > > > IMO, adding a new quirk is cleaner, and adopts the same solution > > that it is currently used by other drivers with Designware IP. > > We already have a bunch of quirk properties. What's one more, sigh. So > if that's what you want, fine. > > Rob It sounds that this is the last piece for us to have everything needed at the drivers in order to provide upstream support for the Hikey 970 USB hub. Could you please merge it? Thanks, Mauro
Mauro Carvalho Chehab <mchehab+huawei@kernel.org> writes: > Ping. > > Felipe, > > Em Thu, 17 Sep 2020 08:47:48 -0600 > Rob Herring <robh@kernel.org> escreveu: > >> On Thu, Sep 17, 2020 at 1:18 AM Mauro Carvalho Chehab >> <mchehab+huawei@kernel.org> wrote: >> > > >> > IMO, adding a new quirk is cleaner, and adopts the same solution >> > that it is currently used by other drivers with Designware IP. >> >> We already have a bunch of quirk properties. What's one more, sigh. So >> if that's what you want, fine. >> >> Rob > > It sounds that this is the last piece for us to have everything > needed at the drivers in order to provide upstream support for > the Hikey 970 USB hub. > > Could you please merge it? Pushed to testing/next. I'll send a pull request to Greg this week, unless something goes terribly wrong on linux-next