Re: [PATCH v2] usb: host: xhci: mvebu: make USB 3.0 PHY optional for Armada 3720

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Feb 01, 2021 at 04:08:03PM +0100, Pali Rohár wrote:
> Older ATF does not provide SMC call for USB 3.0 phy power on functionality
> and therefore initialization of xhci-hcd is failing when older version of
> ATF is used. In this case phy_power_on() function returns -EOPNOTSUPP.
> 
> [    3.108467] mvebu-a3700-comphy d0018300.phy: unsupported SMC call, try updating your firmware
> [    3.117250] phy phy-d0018300.phy.0: phy poweron failed --> -95
> [    3.123465] xhci-hcd: probe of d0058000.usb failed with error -95
> 
> This patch introduces a new plat_setup callback for xhci platform drivers
> which is called prior calling usb_add_hcd() function. This function at its
> beginning skips PHY init if hcd->skip_phy_initialization is set.
> 
> Current init_quirk callback for xhci platform drivers is called from
> xhci_plat_setup() function which is called after chip reset completes.
> It happens in the middle of the usb_add_hcd() function and therefore this
> callback cannot be used for setting if PHY init should be skipped or not.
> 
> For Armada 3720 this patch introduce a new xhci_mvebu_a3700_plat_setup()
> function configured as a xhci platform plat_setup callback. This new
> function calls phy_power_on() and in case it returns -EOPNOTSUPP then
> XHCI_SKIP_PHY_INIT quirk is set to instruct xhci-plat to skip PHY
> initialization.
> 
> This patch fixes above failure by ignoring 'not supported' error in
> xhci-hcd driver. In this case it is expected that phy is already power on.
> 
> It fixes initialization of xhci-hcd on Espressobin boards where is older
> Marvell's Arm Trusted Firmware without SMC call for USB 3.0 phy power.
> 
> This is regression introduced in commit bd3d25b07342 ("arm64: dts: marvell:
> armada-37xx: link USB hosts with their PHYs") where USB 3.0 phy was defined
> and therefore xhci-hcd on Espressobin with older ATF started failing.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Tested-by: Tomasz Maciej Nowak <tmn505@gmail.com>
> Fixes: bd3d25b07342 ("arm64: dts: marvell: armada-37xx: link USB hosts with their PHYs")
> Cc: <stable@vger.kernel.org> # 5.1+: ea17a0f153af: phy: marvell: comphy: Convert internal SMCC firmware return codes to errno
> Cc: <stable@vger.kernel.org> # 5.1+: f768e718911e: usb: host: xhci-plat: add priv quirk for skip PHY initialization


Mathias, any objection for me taking this now to get into 5.11-final?

thanks,

greg k-h