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Subject[PATCH] usb: core: Add "quirks" parameter for usbcore
Date
Trying quirks in usbcore needs to rebuild the driver or the entire
kernel if it's builtin. It can save a lot of time if usbcore has similar
ability like "usbhid.quirks=" and "usb-storage.quirks=".

Rename the original quirk detection function to "static" as we introduce
this new "dynamic" function.

Now users can use "usbcore.quirks=" as short term workaround before the
next kernel release.

This is inspired by usbhid and usb-storage.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
Documentation/admin-guide/kernel-parameters.txt | 55 +++++++++++++
drivers/usb/core/quirks.c | 103 ++++++++++++++++++++++--
include/linux/usb/quirks.h | 2 +
3 files changed, 154 insertions(+), 6 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 6571fbfdb2a1..f1cb31aa25e3 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4302,6 +4302,61 @@

usbcore.nousb [USB] Disable the USB subsystem

+ usbcore.quirks=
+ [USB] A list of quirks entries to supplement or
+ override the built-in usb core quirk 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 core quirk flag as follows:
+ a = USB_QUIRK_STRING_FETCH_255 (string
+ descriptors must not be fetched using
+ a 255-byte read);
+ b = USB_QUIRK_RESET_RESUME (device can't resume
+ correctly so reset it instead);
+ c = USB_QUIRK_NO_SET_INTF (device can't handle
+ Set-Interface requests);
+ d = USB_QUIRK_CONFIG_INTF_STRINGS (device can't
+ handle its Configuration or Interface
+ strings);
+ e = USB_QUIRK_RESET (device can't be reset
+ (e.g morph devices), don't use reset);
+ f = USB_QUIRK_HONOR_BNUMINTERFACES (device has
+ more interface descriptions than the
+ bNumInterfaces count, and can't handle
+ talking to these interfaces);
+ g = USB_QUIRK_DELAY_INIT (device needs a pause
+ during initialization, after we read
+ the device descriptor);
+ h = USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL (For
+ high speed and super speed interrupt
+ endpoints, the USB 2.0 and USB 3.0 spec
+ require the interval in microframes (1
+ microframe = 125 microseconds) to be
+ calculated as interval = 2 ^
+ (bInterval-1).
+ Devices with this quirk report their
+ bInterval as the result of this
+ calculation instead of the exponent
+ variable used in the calculation);
+ i = USB_QUIRK_DEVICE_QUALIFIER (device can't
+ handle device_qualifier descriptor
+ requests);
+ j = USB_QUIRK_IGNORE_REMOTE_WAKEUP (device
+ generates spurious wakeup, ignore
+ remote wakeup capability);
+ k = USB_QUIRK_NO_LPM (device can't handle Link
+ Power Management);
+ l = USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL
+ (Device reports its bInterval as linear
+ frames instead of the USB 2.0
+ calculation);
+ m = USB_QUIRK_DISCONNECT_SUSPEND (Device needs
+ to be disconnected before suspend to
+ prevent spurious wakeup)
+ Example: quirks=0781:5580:bk,0a5c:5834:gij
+
usbhid.mousepoll=
[USBHID] The interval which mice are to be polled at.

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index f1dbab6f798f..0fd31aa2baa1 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -11,6 +11,12 @@
#include <linux/usb/hcd.h>
#include "usb.h"

+/* Quirks specified at module load time */
+static char *quirks_param[MAX_USB_BOOT_QUIRKS];
+module_param_array_named(quirks, quirks_param, charp, NULL, 0444);
+MODULE_PARM_DESC(quirks, "Add/modify USB quirks by specifying
+ quirks=vendorID:productID:quirks");
+
/* 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
@@ -310,8 +316,8 @@ static int usb_amd_resume_quirk(struct usb_device *udev)
return 0;
}

-static u32 __usb_detect_quirks(struct usb_device *udev,
- const struct usb_device_id *id)
+static u32 usb_detect_static_quirks(struct usb_device *udev,
+ const struct usb_device_id *id)
{
u32 quirks = 0;

@@ -329,23 +335,108 @@ static u32 __usb_detect_quirks(struct usb_device *udev,
return quirks;
}

+/* Works only for digits and letters, but small and fast */
+#define TOLOWER(x) ((x) | 0x20)
+
+static u32 usb_detect_dynamic_quirks(struct usb_device *udev)
+{
+ u16 dev_vid = le16_to_cpu(udev->descriptor.idVendor);
+ u16 dev_pid = le16_to_cpu(udev->descriptor.idProduct);
+ u16 quirk_vid, quirk_pid;
+ char quirks[32];
+ char *p;
+ u32 flags = 0;
+ int n, m;
+
+ for (n = 0; n < MAX_USB_BOOT_QUIRKS && quirks_param[n]; n++) {
+ m = sscanf(quirks_param[n], "%hx:%hx:%s",
+ &quirk_vid, &quirk_pid, quirks);
+ if (m != 3)
+ pr_warn("Could not parse USB quirk module param %s\n",
+ quirks_param[n]);
+
+ if (quirk_vid == dev_vid && quirk_pid == dev_pid)
+ break;
+ }
+ if (n == MAX_USB_BOOT_QUIRKS || !quirks_param[n])
+ return 0;
+
+ p = quirks;
+
+ /* Collect the flags */
+ for (; *p; p++) {
+ switch (TOLOWER(*p)) {
+ case 'a':
+ flags |= USB_QUIRK_STRING_FETCH_255;
+ break;
+ case 'b':
+ flags |= USB_QUIRK_RESET_RESUME;
+ break;
+ case 'c':
+ flags |= USB_QUIRK_NO_SET_INTF;
+ break;
+ case 'd':
+ flags |= USB_QUIRK_CONFIG_INTF_STRINGS;
+ break;
+ case 'e':
+ flags |= USB_QUIRK_RESET;
+ break;
+ case 'f':
+ flags |= USB_QUIRK_HONOR_BNUMINTERFACES;
+ break;
+ case 'g':
+ flags |= USB_QUIRK_DELAY_INIT;
+ break;
+ case 'h':
+ flags |= USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL;
+ break;
+ case 'i':
+ flags |= USB_QUIRK_DEVICE_QUALIFIER;
+ break;
+ case 'j':
+ flags |= USB_QUIRK_IGNORE_REMOTE_WAKEUP;
+ break;
+ case 'k':
+ flags |= USB_QUIRK_NO_LPM;
+ break;
+ case 'l':
+ flags |= USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL;
+ break;
+ case 'm':
+ flags |= USB_QUIRK_DISCONNECT_SUSPEND;
+ break;
+ /* Ignore unrecognized flag characters */
+ }
+ }
+
+ return flags;
+}
+
/*
* Detect any quirks the device has, and do any housekeeping for it if needed.
*/
void usb_detect_quirks(struct usb_device *udev)
{
- udev->quirks = __usb_detect_quirks(udev, usb_quirk_list);
+ udev->quirks = usb_detect_dynamic_quirks(udev);
+
+ if (udev->quirks) {
+ dev_dbg(&udev->dev, "Dynamic USB quirks for this device: %x\n",
+ udev->quirks);
+ return;
+ }
+
+ udev->quirks = usb_detect_static_quirks(udev, usb_quirk_list);

/*
* Pixart-based mice would trigger remote wakeup issue on AMD
* Yangtze chipset, so set them as RESET_RESUME flag.
*/
if (usb_amd_resume_quirk(udev))
- udev->quirks |= __usb_detect_quirks(udev,
+ udev->quirks |= usb_detect_static_quirks(udev,
usb_amd_resume_quirk_list);

if (udev->quirks)
- dev_dbg(&udev->dev, "USB quirks for this device: %x\n",
+ dev_dbg(&udev->dev, "Static USB quirks for this device: %x\n",
udev->quirks);

#ifdef CONFIG_USB_DEFAULT_PERSIST
@@ -362,7 +453,7 @@ void usb_detect_interface_quirks(struct usb_device *udev)
{
u32 quirks;

- quirks = __usb_detect_quirks(udev, usb_interface_quirk_list);
+ quirks = usb_detect_static_quirks(udev, usb_interface_quirk_list);
if (quirks == 0)
return;

diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index f1fcec2fd5f8..40254f2fafb2 100644
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -8,6 +8,8 @@
#ifndef __LINUX_USB_QUIRKS_H
#define __LINUX_USB_QUIRKS_H

+#define MAX_USB_BOOT_QUIRKS 4
+
/* string descriptors must not be fetched using a 255-byte read */
#define USB_QUIRK_STRING_FETCH_255 BIT(0)

--
2.14.1
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