Hi Josua, Alan, as we discussed earlier devices which need to be switched must not be reset. Currently I think only the storage driver is affected. Ideally we would not put all those devices into the quirks list. I'd prefer the user space tools making the switch to tell the kernel that the new device is quirky. What kind of API for that would you prefer? Regards Oliver -- >From ff39d073bda410d032d17711a7deb1761f451bae Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oliver@xxxxxxxxxx> Date: Mon, 14 Dec 2009 17:59:11 +0100 Subject: [PATCH] usb-storage:Never reset devices that will morph to an old mode Some devices must be switched to a new mode to fully use them. A reset would make them revert to the old mode. Therefore a reset must not be used for error handling with such devices. Signed-off-by: Oliver Neukum <oliver@xxxxxxxxxx> --- drivers/usb/core/quirks.c | 3 ++- drivers/usb/storage/transport.c | 6 ++++++ include/linux/usb/quirks.h | 3 +++ 3 files changed, 11 insertions(+), 1 deletions(-) diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index ab93918..0b68922 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -120,6 +120,7 @@ void usb_detect_quirks(struct usb_device *udev) * for all devices. It will affect things like hub resets * and EMF-related port disables. */ - udev->persist_enabled = 1; + if (!(udev->quirks & USB_QUIRK_RESET_MORPHS)) + udev->persist_enabled = 1; #endif /* CONFIG_PM */ } diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c index cc313d1..4680381 100644 --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -47,6 +47,8 @@ #include <linux/errno.h> #include <linux/slab.h> +#include <linux/usb/quirks.h> + #include <scsi/scsi.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_device.h> @@ -1297,6 +1299,10 @@ int usb_stor_port_reset(struct us_data *us) { int result; + /*for these devices we must use the class specific method */ + if (us->pusb_dev->quirks & USB_QUIRK_RESET_MORPHS) + return -EPERM; + result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); if (result < 0) US_DEBUGP("unable to lock device for reset: %d\n", result); diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h index 2526f3b..0a555dd 100644 --- a/include/linux/usb/quirks.h +++ b/include/linux/usb/quirks.h @@ -19,4 +19,7 @@ /* device can't handle its Configuration or Interface strings */ #define USB_QUIRK_CONFIG_INTF_STRINGS 0x00000008 +/*device will morph if reset, don't use reset for handling errors */ +#define USB_QUIRK_RESET_MORPHS 0x00000010 + #endif /* __LINUX_USB_QUIRKS_H */ -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html