drivers/usb/storage/uas-detect.h

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