Re: [PATCH] phy: usb: fix Broadcom driver table indexing error

From: Florian Fainelli
Date: Thu Oct 03 2024 - 18:47:59 EST


On 10/3/24 14:17, Sam Edwards wrote:
The Broadcom USB PHY driver contains a lookup table
(`reg_bits_map_tables`) to resolve register bitmaps unique to certain
versions of the USB PHY as found in various Broadcom chip families.
Historically, this table was just kept carefully in sync with the
"selector" enum every time the latter changed to ensure consistency.
However, a recent commit (see 'fixes' tag) introduced two new
enumerators but did not adjust the array for BCM4908, thus breaking the
xHCI controller (and boot process) on this platform and revealing the
fragility of this approach.

Since these arrays are a little sparse (many elements are zero) and the
position of the array elements is significant only insofar as they agree
with the enumerators, designated initializers are a better fit than
positional initializers here. Convert this table accordingly, fixing the
boot-time crash on BCM4908 in the process.

Fixes: 4536fe9640b6 ("phy: usb: suppress OC condition for 7439b2")
Signed-off-by: Sam Edwards <CFSworks@xxxxxxxxx>

Thanks a bunch for the fix, good catch! Sorry to ask you this, but since this is intended to be backported to stable trees at some point, would you mind breaking this up in two commits:

- one which is easy to review and audit and which adjusts the BCM4908 entry
- another one which converts to using designated index constants?

Thanks!
--
Florian