Re: [PATCH RFC] USB: cdc-acm: Fix bit overlap and move quirk definitions to header

[Greg KH]

On Wed, May 06, 2026 at 05:32:13PM +0800, Wentao Guan wrote:
> The VENDOR_CLASS_DATA_IFACE and ALWAYS_POLL_CTRL quirk flags added in
> commit f58752ebcb35 ("USB: cdc-acm: Add quirks for Yoga Book 9 14IAH10
> INGENIC touchscreen") were placed inside the acm_ctrl_msg() function
> rather than in the header with the other quirk flags.  Then, their
> values (BIT(9) and BIT(10)) collided with NO_UNION_12 which is already
> BIT(9).
> 
> Move the definitions to drivers/usb/class/cdc-acm.h where they belong
> and shift them to BIT(10) and BIT(11) to avoid the overlap.
> 
> Fixes: f58752ebcb35 ("USB: cdc-acm: Add quirks for Yoga Book 9 14IAH10 INGENIC touchscreen")
> Cc: stable@xxxxxxxxxxxxxxx

Why is this needed for stable?  What bug does this "fix"?

thanks,

greg k-h