Re: [PATCH v6] usb: core: Add "quirks" parameter for usbcore

From: Kai Heng Feng
Date: Tue Mar 13 2018 - 22:00:22 EST


Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:

On Tue, Mar 13, 2018 at 03:26:19PM +0800, Kai-Heng Feng wrote:
+ 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:

This doesn't really tell me that the specified quirks will be XORed with
the built-in quirks. Maybe something like ...

[USB] A list of quirk entries to augment the
built-in usb core quirk list. List entries are
separated by commas. Each entry has the form
VendorID:ProductID:Flags. The IDs are 4-digit hex
numbers and Flags is a set of letters. Each letter
will change the built-in quirk; setting it if it is
clear and clearing it if it is set. The letters
have the following meanings:

Thanks, will update the description to specify the XOR behavior.


+ /* Each entry consists of VID:PID:flags */
+ field = strsep(&p, ":");
+ if (!field)
+ break;
+
+ if (kstrtou16(field, 16, &vid))
+ break;
+
+ field = strsep(&p, ":");
+ if (!field)
+ break;
+
+ if (kstrtou16(field, 16, &pid))
+ break;

Is there a reason to not use sscanf here like hid-quirks.c does?

Actually I use sscanf in previous patch version. Using kstrto* isn't needed anymore, I'll use sscanf in next version.

Kai-Heng