forked from Minki/linux
82aa0387d5
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>
41 lines
1.1 KiB
C
41 lines
1.1 KiB
C
#include <linux/usb.h>
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#include <linux/usb/hcd.h>
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static int uas_is_interface(struct usb_host_interface *intf)
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{
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return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
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intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
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intf->desc.bInterfaceProtocol == USB_PR_UAS);
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}
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static int uas_isnt_supported(struct usb_device *udev)
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{
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struct usb_hcd *hcd = bus_to_hcd(udev->bus);
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dev_warn(&udev->dev, "The driver for the USB controller %s does not "
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"support scatter-gather which is\n",
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hcd->driver->description);
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dev_warn(&udev->dev, "required by the UAS driver. Please try an"
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"alternative USB controller if you wish to use UAS.\n");
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return -ENODEV;
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}
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static int uas_find_uas_alt_setting(struct usb_interface *intf)
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{
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int i;
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struct usb_device *udev = interface_to_usbdev(intf);
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int sg_supported = udev->bus->sg_tablesize != 0;
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for (i = 0; i < intf->num_altsetting; i++) {
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struct usb_host_interface *alt = &intf->altsetting[i];
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if (uas_is_interface(alt)) {
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if (!sg_supported)
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return uas_isnt_supported(udev);
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return alt->desc.bAlternateSetting;
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}
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}
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return -ENODEV;
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}
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