On Tue, 21 Nov 2023 11:21:53 +0100, Hans de Goede wrote: > > Hi, > > On 11/21/23 10:52, Takashi Iwai wrote: > > 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 > > AFAIK further up in the thread (or a related thread) there > already was consensus to do this. Someone just needs to > write the patch. Well, is there any user of this new led_classdev.color field? The value read from fwnode is stored there, but as far as I see, there seems no real user, so far. If it's still unused, we can do the whole revert -- which is cleaner. Takashi > > 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). > > The new color attribute causing the conflict has only > been in 6.6 so there likely aren't any users of it yet > and since dropping it would be backported to 6.6.y > there shouldn't be any future users of it either, since > any 6.6 users presumably will use 6.6.y and not 6.6.0 > > > IMO, 2 would be the least harm, as the class sysfs entry was > > introduced since 6.6. > > Ack. > > > I guess this is what Jean-Jacques suggested. > > Right. > > > 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. > > If I have read the thread correctly it is not important the value > it represents is used internally in the LED subsystem and userspace > does not really need it. > > Regards, > > Hans > > >
