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

[Kai Heng Feng]

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