Re: [PATCH v5 4/5] usb: host: Stops USB controller init if PLL fails to lock

From: Alan Stern
Date: Wed May 08 2019 - 12:51:32 EST


On Wed, 8 May 2019, Yinbo Zhu wrote:

> From: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
>
> USB erratum-A006918 workaround tries to start internal PHY inside
> uboot (when PLL fails to lock). However, if the workaround also
> fails, then USB initialization is also stopped inside Linux.
> Erratum-A006918 workaround failure creates "fsl,erratum_a006918"
> node in device-tree. Presence of this node in device-tree is
> used to stop USB controller initialization in Linux
>
> Signed-off-by: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
> Signed-off-by: Suresh Gupta <suresh.gupta@xxxxxxxxxxxxx>
> Signed-off-by: Yinbo Zhu <yinbo.zhu@xxxxxxx>
> ---
> Change in v5:
> use dev_warn() instead of pr_warn()
>
> drivers/usb/host/ehci-fsl.c | 5 +++++
> drivers/usb/host/fsl-mph-dr-of.c | 3 ++-
> 2 files changed, 7 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> index 1634ac8..90550a6 100644
> --- a/drivers/usb/host/ehci-fsl.c
> +++ b/drivers/usb/host/ehci-fsl.c
> @@ -236,6 +236,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> portsc |= PORT_PTS_PTW;
> /* fall through */
> case FSL_USB2_PHY_UTMI:
> + if (pdata->has_fsl_erratum_a006918) {
> + dev_warn(dev, "USB PHY clock invalid\n");
> + return -EINVAL;
> + }
> +

You need to add a "Fall through" comment between these two cases.

> case FSL_USB2_PHY_UTMI_DUAL:
> /* PHY_CLK_VALID bit is de-featured from all controller
> * versions below 2.4 and is to be checked only for

Alan Stern