On Tue, 21 Nov 2023 10:19:03 +0100, Thorsten Leemhuis wrote: > > Takashi, Jean-Jacques Hiblot, Lee, > > On 20.11.23 14:53, Takashi Iwai wrote: > > On Mon, 06 Nov 2023 14:19:08 +0100, > > Bagas Sanjaya wrote: > >> On Sat, Nov 04, 2023 at 01:01:56PM +0100, Jean-Jacques Hiblot wrote: > >>> On 29/10/2023 02:48, Bagas Sanjaya wrote: > >>>> On Thu, Oct 26, 2023 at 02:55:06PM +0700, Bagas Sanjaya wrote: > >>>>> The culprit seems to be commit c7d80059b086c4986cd994a1973ec7a5d75f8eea, which introduces a new 'color' attribute for led sysfs class devices. The problem is that the system76-acpi platform driver tries to create the exact same sysfs attribute itself for the system76_acpi::kbd_backlight device, leading to the conflict. For testing purposes, I've just rebuilt the kernel with the system76-apci color attribute renamed to kb_color, and that fixes the issue. > >>>> > >>>> Jean-Jacques Hiblot, would you like to take a look on this regression, > >>>> since you authored the culprit? > > > >>> The offending commit stores the color in struct led_classdev and exposes it > >>> via sysfs. It was part of a series that create a RGB leds from multiple > >>> single-color LEDs. for this series, we need the color information but we > >>> don't really need to expose it it via sysfs. In order to fix the issue, we > >>> can remove the 'color' attribute from the sysfs. > >> > >> OK, see you in the patch! > > > > Is there a patch available? > > Not that I know of. Could not find anything on lore either. > > > This bug hits for a few Logitech keyboard models, too, and it makes > > 6.6 kernel unsable for them, as hid-lg-g15 driver probe fails due to > > this bug: > > https://bugzilla.kernel.org/show_bug.cgi?id=218155 > > > > We need a quick fix for 6.6.x. > > Given that Jean-Jacques Hiblot (the author of the culprit) and Lee (who > committed it and sent it to Linus) know about this for a while already > without doing anything about it, I wonder if someone should just send a > revert to Linus (unless of course that is likely to introduce a > regression on its own). > > Takashi, could you maybe do this, unless a fix shows up real soon? I can, but we need to decide which way to go. There are several options: 1. Revert the commit c7d80059b086; this drops led class color sysfs entries. Also the store of led_cdev->color from fwnode is dropped, too. 2. Drop only led class color sysfs entries; a partial revert of c7d80059b086 above 3. Rename conflicting sysfs entries in drivers; e.g. color -> kb_color for hid-lg-g15 and system76_acpi In either way, we'd break user-space (sysfs). IMO, 2 would be the least harm, as the class sysfs entry was introduced since 6.6. I guess this is what Jean-Jacques suggested. But I'm not sure how important this new class sysfs entry is; it has to be clarified from leds people who actually use / wanted the feature. 3 was already confirmed to work on both bug reports. OTOH, it's not clear whether we can neglect (potentially) already existing users. Takashi > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) > > P.S.: /me should have followed up on this earlier... :-/ > -- > Everything you wanna know about Linux kernel regression tracking: > https://linux-regtracking.leemhuis.info/about/#tldr > If I did something stupid, please tell me, as explained on that page. >
