[PATCH v2 0/2] ARM: shmobile: r8a7791: add for USB-DMAC

[PATCH v2 0/2] ARM: shmobile: r8a7791: add for USB-DMAC

[Yoshihiro Shimoda]

This patch set is based on renesas.git / renesas-devel-20150406-v4.0-rc6
tag. (commit id = 8acf8f0880b6a142e6291b9a7d81f2f38c9425ac)

This patch set is related to the usb-dmac driver and renesas_usbhs driver.
And these drivers have been merged in each subsystem:

[ slave-dma repository ]
https://git.kernel.org/cgit/linux/kernel/git/vkoul/slave-dma.git/commit/?h=for-linus&id§267831565030ab94dab76eb1afe5d4b63a1009
https://git.kernel.org/cgit/linux/kernel/git/vkoul/slave-dma.git/commit/?h=for-linus&id\f1c8ff32fa29e425b4938934c21afdb81104431

[ usb repository ]
https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testing/next&idz96b78464bd8ba72c1c3095c543c1402db59e35
https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testing/next&id›53d9af7aac09cf249d72bfbf15f08e47c4f7fe
https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testing/next&id«330cf3888d8e0779fa05a243d53ba9f53a7ba9

Changes from v1:
 - Rebase the latest renesas-devel tag.

Yoshihiro Shimoda (2):
  ARM: shmobile: r8a7791: add USB-DMAC device nodes
  ARM: shmobile: r8a7791: Enable DMA for HSUSB

 arch/arm/boot/dts/r8a7791.dtsi | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

-- 
1.9.1

Re: [PATCH v2 0/2] ARM: shmobile: r8a7791: add for USB-DMAC

[Laurent Pinchart]

Hello Shimoda-san,

(Dropping the DT maintainers from CC and adding Linus Walleij, Kishon Vijay 
Abraham and Felipe Balbi)

On Tuesday 07 April 2015 16:53:49 Yoshihiro Shimoda wrote:
> This patch set is based on renesas.git / renesas-devel-20150406-v4.0-rc6
> tag. (commit id = 8acf8f0880b6a142e6291b9a7d81f2f38c9425ac)
> 
> This patch set is related to the usb-dmac driver and renesas_usbhs driver.
> And these drivers have been merged in each subsystem:
> 
> [ slave-dma repository ]
> https://git.kernel.org/cgit/linux/kernel/git/vkoul/slave-dma.git/commit/?h=f
> or-linus&id§267831565030ab94dab76eb1afe5d4b63a1009
> https://git.kernel.org/cgit/linux/kernel/git/vkoul/slave-dma.git/commit/?h> for-linus&id\f1c8ff32fa29e425b4938934c21afdb81104431
> 
> [ usb repository ]
> https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testing
> /next&idz96b78464bd8ba72c1c3095c543c1402db59e35
> https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testin
> g/next&id›53d9af7aac09cf249d72bfbf15f08e47c4f7fe
> https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/commit/?h=testin
> g/next&id«330cf3888d8e0779fa05a243d53ba9f53a7ba9
> 
> Changes from v1:
>  - Rebase the latest renesas-devel tag.
> 
> Yoshihiro Shimoda (2):
>   ARM: shmobile: r8a7791: add USB-DMAC device nodes
>   ARM: shmobile: r8a7791: Enable DMA for HSUSB

I've successfully tested USB-DMAC integration (congratulations for the good 
work !), but ran into several issues that I wanted to discuss with you.

Both issues are I believe related to the fact that the HSUSB and EHCI/OHCI 
controllers share the same PHY and the same pins.

When both drivers are loaded, the following messages are printed to the kernel 
log.

[    8.917418] sh-pfc e6060000.pfc: pin GP_7_23 already requested by 
ee090000.pci; cannot claim for e6590000.usb
[    8.927594] sh-pfc e6060000.pfc: pin-247 (e6590000.usb) status -22
[    8.933913] sh-pfc e6060000.pfc: could not request pin 247 (GP_7_23) from 
group usb0  on device sh-pfc
[    8.943990] renesas_usbhs e6590000.usb: Error applying setting, reverse 
things back

This is caused by the pci0 and hsusb DT nodes referencing the same default pin 
configuration node. There should be no issue in practice as the pin 
configuration is already applied through the other device, but I'd still like 
to find a fix to avoid the error message.

The other issue is that the renesas_hsusb and ehci drivers compete to control 
the same PHY. The phy-rcar-gen2 driver creates two Linux PHYs for each 
physical PHY (called channel in the driver) to ensure that each driver can get 
its own PHY instance. Arbitration is then handled in the PHY .init() handler 
which returns -EBUSY if another driver already controls the channel. The error 
value is propagated up to usbhsc_power_ctrl() where it's then ignored. This 
doesn't look like a good way to handled the shared PHY, but I'm not familiar 
enough with the PHY subsystem to know how to fix it.

>  arch/arm/boot/dts/r8a7791.dtsi | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)

-- 
Regards,

Laurent Pinchart

RE: [PATCH v2 0/2] ARM: shmobile: r8a7791: add for USB-DMAC

[Yoshihiro Shimoda]

Hi Laurent-san,

Thank you for your comment! And, I'm very sorry for the delayed response because I had completely passed over this email...

> Sent: Friday, June 19, 2015 6:39 PM
> 
> Hello Shimoda-san,
> 
> (Dropping the DT maintainers from CC and adding Linus Walleij, Kishon Vijay
> Abraham and Felipe Balbi)
> 
> On Tuesday 07 April 2015 16:53:49 Yoshihiro Shimoda wrote:
< snip >
> 
> I've successfully tested USB-DMAC integration (congratulations for the good
> work !), but ran into several issues that I wanted to discuss with you.

That's great!

> Both issues are I believe related to the fact that the HSUSB and EHCI/OHCI
> controllers share the same PHY and the same pins.
> 
> When both drivers are loaded, the following messages are printed to the kernel
> log.
> 
> [    8.917418] sh-pfc e6060000.pfc: pin GP_7_23 already requested by
> ee090000.pci; cannot claim for e6590000.usb
> [    8.927594] sh-pfc e6060000.pfc: pin-247 (e6590000.usb) status -22
> [    8.933913] sh-pfc e6060000.pfc: could not request pin 247 (GP_7_23) from
> group usb0  on device sh-pfc
> [    8.943990] renesas_usbhs e6590000.usb: Error applying setting, reverse
> things back
> 
> This is caused by the pci0 and hsusb DT nodes referencing the same default pin
> configuration node. There should be no issue in practice as the pin
> configuration is already applied through the other device, but I'd still like
> to find a fix to avoid the error message.

I also would like to avoid the error message.
Fortunately, if I used the patches that Phil-san made, the error message disappeared on Koelsch.

http://www.spinics.net/lists/linux-usb/msg126747.html
http://www.spinics.net/lists/linux-usb/msg126738.html
http://www.spinics.net/lists/linux-usb/msg126740.html

> The other issue is that the renesas_hsusb and ehci drivers compete to control
> the same PHY. The phy-rcar-gen2 driver creates two Linux PHYs for each
> physical PHY (called channel in the driver) to ensure that each driver can get
> its own PHY instance. Arbitration is then handled in the PHY .init() handler
> which returns -EBUSY if another driver already controls the channel. The error
> value is propagated up to usbhsc_power_ctrl() where it's then ignored. This
> doesn't look like a good way to handled the shared PHY, but I'm not familiar
> enough with the PHY subsystem to know how to fix it.

After I applied Phil-san's patches, if I did "unbind/bind" the renesas_hsusb or
the ehci driver, I could change the PHY setting on Koelsch.
However, in case of Lagar, since it doesn't have OTG chip, it still has this issue.
So, I will investigate some related drivers to fix this issue somehow.

Best regards,
Yoshihiro Shimoda

> >  arch/arm/boot/dts/r8a7791.dtsi | 25 +++++++++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> 
> --
> Regards,
> 
> Laurent Pinchart