drivers/usb/storage/uas-detect.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <linux/usb.h>
   3 #include <linux/usb/hcd.h>
   4 #include "usb.h"
   5
   6 static int uas_is_interface(struct usb_host_interface *intf)
   7 {
   8         return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
   9                 intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
  10                 intf->desc.bInterfaceProtocol == USB_PR_UAS);
  11 }
  12
  13 static struct usb_host_interface *uas_find_uas_alt_setting(
  14                 struct usb_interface *intf)
  15 {
  16         int i;
  17
  18         for (i = 0; i < intf->num_altsetting; i++) {
  19                 struct usb_host_interface *alt = &intf->altsetting[i];
  20
  21                 if (uas_is_interface(alt))
  22                         return alt;
  23         }
  24
  25         return NULL;
  26 }
  27
  28 static int uas_find_endpoints(struct usb_host_interface *alt,
  29                               struct usb_host_endpoint *eps[])
  30 {
  31         struct usb_host_endpoint *endpoint = alt->endpoint;
  32         unsigned i, n_endpoints = alt->desc.bNumEndpoints;
  33
  34         for (i = 0; i < n_endpoints; i++) {
  35                 unsigned char *extra = endpoint[i].extra;
  36                 int len = endpoint[i].extralen;
  37                 while (len >= 3) {
  38                         if (extra[1] == USB_DT_PIPE_USAGE) {
  39                                 unsigned pipe_id = extra[2];
  40                                 if (pipe_id > 0 && pipe_id < 5)
  41                                         eps[pipe_id - 1] = &endpoint[i];
  42                                 break;
  43                         }
  44                         len -= extra[0];
  45                         extra += extra[0];
  46                 }
  47         }
  48
  49         if (!eps[0] || !eps[1] || !eps[2] || !eps[3])
  50                 return -ENODEV;
  51
  52         return 0;
  53 }
  54
  55 static int uas_use_uas_driver(struct usb_interface *intf,
  56                               const struct usb_device_id *id,
  57                               unsigned long *flags_ret)
  58 {
  59         struct usb_host_endpoint *eps[4] = { };
  60         struct usb_device *udev = interface_to_usbdev(intf);
  61         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
  62         unsigned long flags = id->driver_info;
  63         struct usb_host_interface *alt;
  64         int r;
  65
  66         alt = uas_find_uas_alt_setting(intf);
  67         if (!alt)
  68                 return 0;
  69
  70         r = uas_find_endpoints(alt, eps);
  71         if (r < 0)
  72                 return 0;
  73
  74         /*
  75          * ASMedia has a number of usb3 to sata bridge chips, at the time of
  76          * this writing the following versions exist:
  77          * ASM1051 - no uas support version
  78          * ASM1051 - with broken (*) uas support
  79          * ASM1053 - with working uas support, but problems with large xfers
  80          * ASM1153 - with working uas support
  81          *
  82          * Devices with these chips re-use a number of device-ids over the
  83          * entire line, so the device-id is useless to determine if we're
  84          * dealing with an ASM1051 (which we want to avoid).
  85          *
  86          * The ASM1153 can be identified by config.MaxPower == 0,
  87          * where as the ASM105x models have config.MaxPower == 36.
  88          *
  89          * Differentiating between the ASM1053 and ASM1051 is trickier, when
  90          * connected over USB-3 we can look at the number of streams supported,
  91          * ASM1051 supports 32 streams, where as early ASM1053 versions support
  92          * 16 streams, newer ASM1053-s also support 32 streams, but have a
  93          * different prod-id.
  94          *
  95          * (*) ASM1051 chips do work with UAS with some disks (with the
  96          *     US_FL_NO_REPORT_OPCODES quirk), but are broken with other disks
  97          */
  98         if (le16_to_cpu(udev->descriptor.idVendor) == 0x174c &&
  99                         (le16_to_cpu(udev->descriptor.idProduct) == 0x5106 ||
 100                          le16_to_cpu(udev->descriptor.idProduct) == 0x55aa)) {
 101                 if (udev->actconfig->desc.bMaxPower == 0) {
 102                         /* ASM1153, do nothing */
 103                 } else if (udev->speed < USB_SPEED_SUPER) {
 104                         /* No streams info, assume ASM1051 */
 105                         flags |= US_FL_IGNORE_UAS;
 106                 } else if (usb_ss_max_streams(&eps[1]->ss_ep_comp) == 32) {
 107                         /* Possibly an ASM1051, disable uas */
 108                         flags |= US_FL_IGNORE_UAS;
 109                 } else {
 110                         /* ASM1053, these have issues with large transfers */
 111                         flags |= US_FL_MAX_SECTORS_240;
 112                 }
 113         }
 114
 115         usb_stor_adjust_quirks(udev, &flags);
 116
 117         if (flags & US_FL_IGNORE_UAS) {
 118                 dev_warn(&udev->dev,
 119                         "UAS is blacklisted for this device, using usb-storage instead\n");
 120                 return 0;
 121         }
 122
 123         if (udev->bus->sg_tablesize == 0) {
 124                 dev_warn(&udev->dev,
 125                         "The driver for the USB controller %s does not support scatter-gather which is\n",
 126                         hcd->driver->description);
 127                 dev_warn(&udev->dev,
 128                         "required by the UAS driver. Please try an other USB controller if you wish to use UAS.\n");
 129                 return 0;
 130         }
 131
 132         if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) {
 133                 dev_warn(&udev->dev,
 134                         "USB controller %s does not support streams, which are required by the UAS driver.\n",
 135                         hcd_to_bus(hcd)->bus_name);
 136                 dev_warn(&udev->dev,
 137                         "Please try an other USB controller if you wish to use UAS.\n");
 138                 return 0;
 139         }
 140
 141         if (flags_ret)
 142                 *flags_ret = flags;
 143
 144         return 1;
 145 }