usb: Add quirk detection based on interface information

When a whole class of devices (possibly from a specific vendor, or
across multiple vendors) require a quirk, explictly listing all devices
in the class make the quirks table unnecessarily large. Fix this by
allowing matching devices based on interface information.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 72 insertions, 21 deletions

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index 32d3adc315f5..cbd15d1d25d3 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -15,17 +15,22 @@
 #include <linux/usb/quirks.h>
 #include "usb.h"
 
-/* List of quirky USB devices.  Please keep this list ordered by:
+/* Lists of quirky USB devices, split in device quirks and interface quirks.
+ * Device quirks are applied at the very beginning of the enumeration process,
+ * right after reading the device descriptor. They can thus only match on device
+ * information.
+ *
+ * Interface quirks are applied after reading all the configuration descriptors.
+ * They can match on both device and interface information.
+ *
+ * Note that the DELAY_INIT and HONOR_BNUMINTERFACES quirks do not make sense as
+ * interface quirks, as they only influence the enumeration process which is run
+ * before processing the interface quirks.
+ *
+ * Please keep the lists ordered by:
  * 	1) Vendor ID
  * 	2) Product ID
  * 	3) Class ID
- *
- * as we want specific devices to be overridden first, and only after that, any
- * class specific quirks.
- *
- * Right now the logic aborts if it finds a valid device in the table, we might
- * want to change that in the future if it turns out that a whole class of
- * devices is broken...
  */
 static const struct usb_device_id usb_quirk_list[] = {
 	/* CBM - Flash disk */
@@ -156,16 +161,53 @@ static const struct usb_device_id usb_quirk_list[] = {
 	{ }  /* terminating entry must be last */
 };
 
-static const struct usb_device_id *find_id(struct usb_device *udev)
+static const struct usb_device_id usb_interface_quirk_list[] = {
+	{ }  /* terminating entry must be last */
+};
+
+static bool usb_match_any_interface(struct usb_device *udev,
+				    const struct usb_device_id *id)
+{
+	unsigned int i;
+
+	for (i = 0; i < udev->descriptor.bNumConfigurations; ++i) {
+		struct usb_host_config *cfg = &udev->config[i];
+		unsigned int j;
+
+		for (j = 0; j < cfg->desc.bNumInterfaces; ++j) {
+			struct usb_interface_cache *cache;
+			struct usb_host_interface *intf;
+
+			cache = cfg->intf_cache[j];
+			if (cache->num_altsetting == 0)
+				continue;
+
+			intf = &cache->altsetting[0];
+			if (usb_match_one_id_intf(udev, intf, id))
+				return true;
+		}
+	}
+
+	return false;
+}
+
+static u32 __usb_detect_quirks(struct usb_device *udev,
+			       const struct usb_device_id *id)
 {
-	const struct usb_device_id *id = usb_quirk_list;
+	u32 quirks = 0;
 
-	for (; id->idVendor || id->bDeviceClass || id->bInterfaceClass ||
-			id->driver_info; id++) {
-		if (usb_match_device(udev, id))
-			return id;
+	for (; id->match_flags; id++) {
+		if (!usb_match_device(udev, id))
+			continue;
+
+		if ((id->match_flags & USB_DEVICE_ID_MATCH_INT_INFO) &&
+		    !usb_match_any_interface(udev, id))
+			continue;
+
+		quirks |= (u32)(id->driver_info);
 	}
-	return NULL;
+
+	return quirks;
 }
 
 /*
@@ -173,14 +215,10 @@ static const struct usb_device_id *find_id(struct usb_device *udev)
  */
 void usb_detect_quirks(struct usb_device *udev)
 {
-	const struct usb_device_id *id = usb_quirk_list;
-
-	id = find_id(udev);
-	if (id)
-		udev->quirks = (u32)(id->driver_info);
+	udev->quirks = __usb_detect_quirks(udev, usb_quirk_list);
 	if (udev->quirks)
 		dev_dbg(&udev->dev, "USB quirks for this device: %x\n",
-				udev->quirks);
+			udev->quirks);
 
 	/* For the present, all devices default to USB-PERSIST enabled */
 #if 0		/* was: #ifdef CONFIG_PM */
@@ -197,3 +235,16 @@ void usb_detect_quirks(struct usb_device *udev)
 		udev->persist_enabled = 1;
 #endif	/* CONFIG_PM */
 }
+
+void usb_detect_interface_quirks(struct usb_device *udev)
+{
+	u32 quirks;
+
+	quirks = __usb_detect_quirks(udev, usb_interface_quirk_list);
+	if (quirks == 0)
+		return;
+
+	dev_dbg(&udev->dev, "USB interface quirks for this device: %x\n",
+		quirks);
+	udev->quirks |= quirks;
+}