USB: usb-storage: add "quirks=" module parameter

This patch (as1163b) adds a "quirks=" module parameter to usb-storage.
This will allow people to make short-term changes to their
unusual_devs list without rebuilding the entire driver.  Testing will
become much easier, and less-sophisticated users will be able to
access their buggy devices after a simple config-file change instead
of having to wait for a new kernel release.

The patch also adds a documentation entry for usb-storage's
"delay_use" parameter, which has been around for years but but was
never listed among the kernel parameters.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0b3f6711d2f1a5a084ddab87e3ce27b5efae72fb..8eb6e35405cdf0e2a4f4ccf8d2483efa8045272e 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -91,6 +91,7 @@ parameter is applicable:
        SUSPEND System suspend states are enabled.
        FTRACE  Function tracing enabled.
        TS      Appropriate touchscreen support is enabled.
+       UMS     USB Mass Storage support is enabled.
        USB     USB support is enabled.
        USBHID  USB Human Interface Device support is enabled.
        V4L     Video For Linux support is enabled.
@@ -2383,6 +2384,34 @@ and is between 256 and 4096 characters. It is defined in the file
        usbhid.mousepoll=
                        [USBHID] The interval which mice are to be polled at.
 
+       usb-storage.delay_use=
+                       [UMS] The delay in seconds before a new device is
+                       scanned for Logical Units (default 5).
+
+       usb-storage.quirks=
+                       [UMS] A list of quirks entries to supplement or
+                       override the built-in unusual_devs list.  List
+                       entries are separated by commas.  Each entry has
+                       the form VID:PID:Flags where VID and PID are Vendor
+                       and Product ID values (4-digit hex numbers) and
+                       Flags is a set of characters, each corresponding
+                       to a common usb-storage quirk flag as follows:
+                               c = FIX_CAPACITY (decrease the reported
+                                       device capacity by one sector);
+                               i = IGNORE_DEVICE (don't bind to this
+                                       device);
+                               l = NOT_LOCKABLE (don't try to lock and
+                                       unlock ejectable media);
+                               m = MAX_SECTORS_64 (don't transfer more
+                                       than 64 sectors = 32 KB at a time);
+                               r = IGNORE_RESIDUE (the device reports
+                                       bogus residue values);
+                               s = SINGLE_LUN (the device has only one
+                                       Logical Unit);
+                               w = NO_WP_DETECT (don't test whether the
+                                       medium is write-protected).
+                       Example: quirks=0419:aaf5:rl,0421:0433:rc
+
        add_efi_memmap  [EFI; x86-32,X86-64] Include EFI memory map in
                        kernel's map of available physical RAM.
 

diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 27016fd2cad19003852154d23afc3d3f75573c9e..eb1a53a3e5ca3135b0173ece397767b88657f0c4 100644 (file)
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -113,6 +113,16 @@ static unsigned int delay_use = 5;
 module_param(delay_use, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(delay_use, "seconds to delay before using a new device");
 
+static char *quirks;
+module_param(quirks, charp, S_IRUGO);
+MODULE_PARM_DESC(quirks, "supplemental list of device IDs and their quirks");
+
+struct quirks_entry {
+       u16     vid, pid;
+       u32     fflags;
+};
+static struct quirks_entry *quirks_list, *quirks_end;
+
 
 /*
  * The entries in this table correspond, line for line,
@@ -473,6 +483,30 @@ static int associate_dev(struct us_data *us, struct usb_interface *intf)
        return 0;
 }
 
+/* Adjust device flags based on the "quirks=" module parameter */
+static void adjust_quirks(struct us_data *us)
+{
+       u16 vid, pid;
+       struct quirks_entry *q;
+       unsigned int mask = (US_FL_FIX_CAPACITY | US_FL_IGNORE_DEVICE |
+                       US_FL_NOT_LOCKABLE | US_FL_MAX_SECTORS_64 |
+                       US_FL_IGNORE_RESIDUE | US_FL_SINGLE_LUN |
+                       US_FL_NO_WP_DETECT);
+
+       vid = le16_to_cpu(us->pusb_dev->descriptor.idVendor);
+       pid = le16_to_cpu(us->pusb_dev->descriptor.idProduct);
+
+       for (q = quirks_list; q != quirks_end; ++q) {
+               if (q->vid == vid && q->pid == pid) {
+                       us->fflags = (us->fflags & ~mask) | q->fflags;
+                       dev_info(&us->pusb_intf->dev, "Quirks match for "
+                                       "vid %04x pid %04x: %x\n",
+                                       vid, pid, q->fflags);
+                       break;
+               }
+       }
+}
+
 /* Find an unusual_dev descriptor (always succeeds in the current code) */
 static struct us_unusual_dev *find_unusual(const struct usb_device_id *id)
 {
@@ -497,6 +531,7 @@ static int get_device_info(struct us_data *us, const struct usb_device_id *id)
                        idesc->bInterfaceProtocol :
                        unusual_dev->useTransport;
        us->fflags = USB_US_ORIG_FLAGS(id->driver_info);
+       adjust_quirks(us);
 
        if (us->fflags & US_FL_IGNORE_DEVICE) {
                printk(KERN_INFO USB_STORAGE "device ignored\n");
@@ -1061,10 +1096,88 @@ static struct usb_driver usb_storage_driver = {
        .soft_unbind =  1,
 };
 
+/* Works only for digits and letters, but small and fast */
+#define TOLOWER(x) ((x) | 0x20)
+
+static void __init parse_quirks(void)
+{
+       int n, i;
+       char *p;
+
+       if (!quirks)
+               return;
+
+       /* Count the ':' characters to get 2 * the number of entries */
+       n = 0;
+       for (p = quirks; *p; ++p) {
+               if (*p == ':')
+                       ++n;
+       }
+       n /= 2;
+       if (n == 0)
+               return;         /* Don't allocate 0 bytes */
+
+       quirks_list = kmalloc(n * sizeof(*quirks_list), GFP_KERNEL);
+       if (!quirks_list)
+               return;
+
+       p = quirks;
+       quirks_end = quirks_list;
+       for (i = 0; i < n && *p; ++i) {
+               unsigned f = 0;
+
+               /* Each entry consists of VID:PID:flags */
+               quirks_end->vid = simple_strtoul(p, &p, 16);
+               if (*p != ':')
+                       goto skip_to_next;
+               quirks_end->pid = simple_strtoul(p+1, &p, 16);
+               if (*p != ':')
+                       goto skip_to_next;
+
+               while (*++p && *p != ',') {
+                       switch (TOLOWER(*p)) {
+                       case 'c':
+                               f |= US_FL_FIX_CAPACITY;
+                               break;
+                       case 'i':
+                               f |= US_FL_IGNORE_DEVICE;
+                               break;
+                       case 'l':
+                               f |= US_FL_NOT_LOCKABLE;
+                               break;
+                       case 'm':
+                               f |= US_FL_MAX_SECTORS_64;
+                               break;
+                       case 'r':
+                               f |= US_FL_IGNORE_RESIDUE;
+                               break;
+                       case 's':
+                               f |= US_FL_SINGLE_LUN;
+                               break;
+                       case 'w':
+                               f |= US_FL_NO_WP_DETECT;
+                               break;
+                       /* Ignore unrecognized flag characters */
+                       }
+               }
+               quirks_end->fflags = f;
+               ++quirks_end;
+
+ skip_to_next:
+               /* Entries are separated by commas */
+               while (*p) {
+                       if (*p++ == ',')
+                               break;
+               }
+       } /* for (i = 0; ...) */
+}
+
 static int __init usb_stor_init(void)
 {
        int retval;
+
        printk(KERN_INFO "Initializing USB Mass Storage driver...\n");
+       parse_quirks();
 
        /* register the driver, return usb_register return code if error */
        retval = usb_register(&usb_storage_driver);