| Message ID | 1397578005-3341-3-git-send-email-laurent.pinchart@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; > -
On Tue, 15 Apr 2014, Stephen Warren wrote: > 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. > */ Yeah. I sort of changed my mind about that. While this sort of overriding is still discouraged, we may as well reduce the penalty for doing it. Alan Stern
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 7ae0c4d..fa2ede7 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -33,15 +33,6 @@ #ifdef CONFIG_PM -static int ehci_hub_control( - struct usb_hcd *hcd, - u16 typeReq, - u16 wValue, - u16 wIndex, - char *buf, - u16 wLength -); - static int persist_enabled_on_companion(struct usb_device *udev, void *unused) { return !udev->maxchild && udev->persist_enabled && @@ -865,7 +856,7 @@ cleanup: #endif /* CONFIG_USB_HCD_TEST_MODE */ /*-------------------------------------------------------------------------*/ -static int ehci_hub_control ( +int ehci_hub_control ( struct usb_hcd *hcd, u16 typeReq, u16 wValue, @@ -1285,6 +1276,7 @@ error_exit: spin_unlock_irqrestore (&ehci->lock, flags); return retval; } +EXPORT_SYMBOL_GPL(ehci_hub_control); static void ehci_relinquish_port(struct usb_hcd *hcd, int portnum) { diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c index 27ac6ad..8325a23 100644 --- a/drivers/usb/host/ehci-tegra.c +++ b/drivers/usb/host/ehci-tegra.c @@ -51,10 +51,6 @@ struct tegra_ehci_soc_config { bool has_hostpc; }; -static int (*orig_hub_control)(struct usb_hcd *hcd, - u16 typeReq, u16 wValue, u16 wIndex, - char *buf, u16 wLength); - struct tegra_ehci_hcd { struct tegra_usb_phy *phy; struct clk *clk; @@ -236,7 +232,7 @@ static int tegra_ehci_hub_control( spin_unlock_irqrestore(&ehci->lock, flags); /* Handle the hub control events here */ - return orig_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength); + return ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength); done: spin_unlock_irqrestore(&ehci->lock, flags); @@ -531,8 +527,6 @@ static int __init ehci_tegra_init(void) * too easy. */ - orig_hub_control = tegra_ehci_hc_driver.hub_control; - tegra_ehci_hc_driver.map_urb_for_dma = tegra_ehci_map_urb_for_dma; tegra_ehci_hc_driver.unmap_urb_for_dma = tegra_ehci_unmap_urb_for_dma; tegra_ehci_hc_driver.hub_control = tegra_ehci_hub_control; diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 9dfc6c1..eee228a 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -872,4 +872,7 @@ extern int ehci_suspend(struct usb_hcd *hcd, bool do_wakeup); extern int ehci_resume(struct usb_hcd *hcd, bool hibernated); #endif /* CONFIG_PM */ +extern int ehci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, + u16 wIndex, char *buf, u16 wLength); + #endif /* __LINUX_EHCI_HCD_H */
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. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- drivers/usb/host/ehci-hub.c | 12 ++---------- drivers/usb/host/ehci-tegra.c | 8 +------- drivers/usb/host/ehci.h | 3 +++ 3 files changed, 6 insertions(+), 17 deletions(-)