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Commit 5d398779 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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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: default avatarOliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d1b5b5c0

drivers/usb/core/quirks.c

+2 −1
Original line number Diff line number Diff line
@@ -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.

	 */

	if (!(udev->quirks & USB_QUIRK_RESET_MORPHS))

		udev->persist_enabled = 1;

#endif	/* CONFIG_PM */

}

drivers/usb/storage/transport.c

+6 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/usb/quirks.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */