diff options
author | Hans de Goede <hdegoede@redhat.com> | 2013-10-21 08:53:31 +0100 |
---|---|---|
committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2014-03-04 15:38:13 -0800 |
commit | 82aa0387d52dd0db2173b844ad52d114807c189b (patch) | |
tree | 428116ccf7b9d5dd6a228d994c6cd6ebdaf03758 /drivers/usb/storage/uas-detect.h | |
parent | e1be067b681054e963dfd01346c0d7fc0f8a63aa (diff) |
uas: Move uas detect code to uas-detect.h
This is a preparation patch for teaching usb-storage to not bind to
uas devices.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb/storage/uas-detect.h')
-rw-r--r-- | drivers/usb/storage/uas-detect.h | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/usb/storage/uas-detect.h b/drivers/usb/storage/uas-detect.h new file mode 100644 index 000000000000..28101c7e6a9f --- /dev/null +++ b/drivers/usb/storage/uas-detect.h @@ -0,0 +1,40 @@ +#include <linux/usb.h> +#include <linux/usb/hcd.h> + +static int uas_is_interface(struct usb_host_interface *intf) +{ + return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE && + intf->desc.bInterfaceSubClass == USB_SC_SCSI && + intf->desc.bInterfaceProtocol == USB_PR_UAS); +} + +static int uas_isnt_supported(struct usb_device *udev) +{ + struct usb_hcd *hcd = bus_to_hcd(udev->bus); + + dev_warn(&udev->dev, "The driver for the USB controller %s does not " + "support scatter-gather which is\n", + hcd->driver->description); + dev_warn(&udev->dev, "required by the UAS driver. Please try an" + "alternative USB controller if you wish to use UAS.\n"); + return -ENODEV; +} + +static int uas_find_uas_alt_setting(struct usb_interface *intf) +{ + int i; + struct usb_device *udev = interface_to_usbdev(intf); + int sg_supported = udev->bus->sg_tablesize != 0; + + for (i = 0; i < intf->num_altsetting; i++) { + struct usb_host_interface *alt = &intf->altsetting[i]; + + if (uas_is_interface(alt)) { + if (!sg_supported) + return uas_isnt_supported(udev); + return alt->desc.bAlternateSetting; + } + } + + return -ENODEV; +} |