[PATCH v2 2/4] USB: EHCI: Export the ehci_hub_control function

[swarren@wwwdotorg.org (Stephen Warren)]

On 04/15/2014 10:06 AM, Laurent Pinchart wrote:
> Platform drivers sometimes need to perform specific handling of hub
> control requests. Make this possible by exporting the ehci_hub_control()
> function which can then be called from a custom hub control handler in
> the default case.

I recall trying to do something like this in the past, but IIRC Alan
Stern didn't want to make this easy for odd drivers needing this unusual
case. Witness the comment right above the context of the modified code
in ehci-tegra.c:

> diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c

/*
 * The Tegra HW has some unusual quirks, which require Tegra-specific
 * workarounds. We override certain hc_driver functions here to
 * achieve that. We explicitly do not enhance ehci_driver_overrides to
 * allow this more easily, since this is an unusual case, and we don't
 * want to encourage others to override these functions by making it
 * too easy.
 */

orig_hub_control = tegra_ehci_hc_driver.hub_control;

> @@ -531,8 +527,6 @@ static int __init ehci_tegra_init(void)
>  	 * too easy.
>  	 */
>  
> -	orig_hub_control = tegra_ehci_hc_driver.hub_control;
> -