Tony,
On 13/12/18 04:17, Tony Lindgren wrote:
> The only case where we can bail out safely without a phy is port_mode
> is OMAP_USBHS_PORT_MODE_UNUSED. It used to be that OMAP_EHCI_PORT_MODE_PHY
> was optional, but that's not a good assumption. We should already have
> "ehci-phy" in all the dts files using OMAP_EHCI_PORT_MODE_PHY.
>
We don't use the PHY at all if port mode is not OMAP_EHCI_PORT_MODE_PHY.
> Note that this fix should not be needed for kernels earlier than v4.19
> as that's when we started moving devices to probe with ti-sysc. We now
> probe l4 interconnects separately, which can cause deferred probe with
> the phy being on a separate l4 interconnect from EHCI.
>
> And old kernels would need to be checked for "ehci-phy" property for
> this fix to avoid regressions.
>
What issue is this patch fixing?
> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Cc: Johan Hovold <johan@xxxxxxxxxx>
> Cc: Ladislav Michl <ladis@xxxxxxxxxxxxxx>
> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> Cc: Roger Quadros <rogerq@xxxxxx>
> Reported-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/usb/host/ehci-omap.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-omap.c b/drivers/usb/host/ehci-omap.c
> --- a/drivers/usb/host/ehci-omap.c
> +++ b/drivers/usb/host/ehci-omap.c
> @@ -159,8 +159,8 @@ static int ehci_hcd_omap_probe(struct platform_device *pdev)
> /* get the PHY device */
> phy = devm_usb_get_phy_by_phandle(dev, "phys", i);
> if (IS_ERR(phy)) {
> - /* Don't bail out if PHY is not absolutely necessary */
> - if (pdata->port_mode[i] != OMAP_EHCI_PORT_MODE_PHY)
> + /* Don't bail out if PHY is unused */
> + if (pdata->port_mode[i] == OMAP_USBHS_PORT_MODE_UNUSED)
> continue;
>
> ret = PTR_ERR(phy);
devm_usb_get_phy_by_phandle() returns -ENODEV if PHY phandle is not present
which would be the case in PHY'less modes (e.g. "ehci-tll" or "ehci-hsic").
This change will error out instead of proceeding normally in those cases.
cheers,
-roger
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