summaryrefslogtreecommitdiff
path: root/drivers/usb/storage/uas-detect.h
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/usb/storage/uas-detect.h
Initial import
Diffstat (limited to 'drivers/usb/storage/uas-detect.h')
-rw-r--r--drivers/usb/storage/uas-detect.h143
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/usb/storage/uas-detect.h b/drivers/usb/storage/uas-detect.h
new file mode 100644
index 000000000..f58caa9e6
--- /dev/null
+++ b/drivers/usb/storage/uas-detect.h
@@ -0,0 +1,143 @@
+#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_find_uas_alt_setting(struct usb_interface *intf)
+{
+ int i;
+
+ for (i = 0; i < intf->num_altsetting; i++) {
+ struct usb_host_interface *alt = &intf->altsetting[i];
+
+ if (uas_is_interface(alt))
+ return alt->desc.bAlternateSetting;
+ }
+
+ return -ENODEV;
+}
+
+static int uas_find_endpoints(struct usb_host_interface *alt,
+ struct usb_host_endpoint *eps[])
+{
+ struct usb_host_endpoint *endpoint = alt->endpoint;
+ unsigned i, n_endpoints = alt->desc.bNumEndpoints;
+
+ for (i = 0; i < n_endpoints; i++) {
+ unsigned char *extra = endpoint[i].extra;
+ int len = endpoint[i].extralen;
+ while (len >= 3) {
+ if (extra[1] == USB_DT_PIPE_USAGE) {
+ unsigned pipe_id = extra[2];
+ if (pipe_id > 0 && pipe_id < 5)
+ eps[pipe_id - 1] = &endpoint[i];
+ break;
+ }
+ len -= extra[0];
+ extra += extra[0];
+ }
+ }
+
+ if (!eps[0] || !eps[1] || !eps[2] || !eps[3])
+ return -ENODEV;
+
+ return 0;
+}
+
+static int uas_use_uas_driver(struct usb_interface *intf,
+ const struct usb_device_id *id,
+ unsigned long *flags_ret)
+{
+ struct usb_host_endpoint *eps[4] = { };
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+ unsigned long flags = id->driver_info;
+ int r, alt;
+
+
+ alt = uas_find_uas_alt_setting(intf);
+ if (alt < 0)
+ return 0;
+
+ r = uas_find_endpoints(&intf->altsetting[alt], eps);
+ if (r < 0)
+ return 0;
+
+ /*
+ * ASMedia has a number of usb3 to sata bridge chips, at the time of
+ * this writing the following versions exist:
+ * ASM1051 - no uas support version
+ * ASM1051 - with broken (*) uas support
+ * ASM1053 - with working uas support, but problems with large xfers
+ * ASM1153 - with working uas support
+ *
+ * Devices with these chips re-use a number of device-ids over the
+ * entire line, so the device-id is useless to determine if we're
+ * dealing with an ASM1051 (which we want to avoid).
+ *
+ * The ASM1153 can be identified by config.MaxPower == 0,
+ * where as the ASM105x models have config.MaxPower == 36.
+ *
+ * Differentiating between the ASM1053 and ASM1051 is trickier, when
+ * connected over USB-3 we can look at the number of streams supported,
+ * ASM1051 supports 32 streams, where as early ASM1053 versions support
+ * 16 streams, newer ASM1053-s also support 32 streams, but have a
+ * different prod-id.
+ *
+ * (*) ASM1051 chips do work with UAS with some disks (with the
+ * US_FL_NO_REPORT_OPCODES quirk), but are broken with other disks
+ */
+ if (le16_to_cpu(udev->descriptor.idVendor) == 0x174c &&
+ (le16_to_cpu(udev->descriptor.idProduct) == 0x5106 ||
+ le16_to_cpu(udev->descriptor.idProduct) == 0x55aa)) {
+ if (udev->actconfig->desc.bMaxPower == 0) {
+ /* ASM1153, do nothing */
+ } else if (udev->speed < USB_SPEED_SUPER) {
+ /* No streams info, assume ASM1051 */
+ flags |= US_FL_IGNORE_UAS;
+ } else if (usb_ss_max_streams(&eps[1]->ss_ep_comp) == 32) {
+ /* Possibly an ASM1051, disable uas */
+ flags |= US_FL_IGNORE_UAS;
+ } else {
+ /* ASM1053, these have issues with large transfers */
+ flags |= US_FL_MAX_SECTORS_240;
+ }
+ }
+
+ usb_stor_adjust_quirks(udev, &flags);
+
+ if (flags & US_FL_IGNORE_UAS) {
+ dev_warn(&udev->dev,
+ "UAS is blacklisted for this device, using usb-storage instead\n");
+ return 0;
+ }
+
+ if (udev->bus->sg_tablesize == 0) {
+ 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 other USB controller if you wish to use UAS.\n");
+ return 0;
+ }
+
+ if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) {
+ dev_warn(&udev->dev,
+ "USB controller %s does not support streams, which are required by the UAS driver.\n",
+ hcd_to_bus(hcd)->bus_name);
+ dev_warn(&udev->dev,
+ "Please try an other USB controller if you wish to use UAS.\n");
+ return 0;
+ }
+
+ if (flags_ret)
+ *flags_ret = flags;
+
+ return 1;
+}