linux_dsm_epyc7002/drivers/usb/storage/uas-detect.h
Hans de Goede 97172a660c uas: Honor no-uas quirk set in usb-storage's quirks module parameter
Falling back from uas to usb-storage requires coordination between uas and
usb-storage, so use usb-storage's quirks module parameter, rather then
requiring the user to pass a param to 2 different modules.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2014-03-04 15:38:17 -08:00

56 lines
1.4 KiB
C

#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include "usb.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;
}
static int uas_use_uas_driver(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usb_device *udev = interface_to_usbdev(intf);
unsigned long flags = id->driver_info;
usb_stor_adjust_quirks(udev, &flags);
if (flags & US_FL_IGNORE_UAS)
return 0;
return uas_find_uas_alt_setting(intf) >= 0;
}