<Note - hope this works - moved to my more opensource friendly email account>
On 2022-09-12 08:20, Mark Pearson wrote:
*From:* Jason A. Donenfeld Jason@zx2c4.com *Sent:* September 12, 2022 6:56 *To:* Sebastian Reichel sebastian.reichel@collabora.com; Mark Pearson mpearson@lenovo.com *Cc:* linux-pm@vger.kernel.org linux-pm@vger.kernel.org; stable@vger.kernel.org stable@vger.kernel.org; Rafael J . Wysocki rafael@kernel.org *Subject:* [External] Re: [PATCH RESEND] power: supply: avoid nullptr deref in __power_supply_is_system_supplied CC+ Mark Pearson from Lenovo Full thread is here: https://lore.kernel.org/all/YwDsy3ZUgTtlKH9r@zx2c4.com/ https://lore.kernel.org/all/YwDsy3ZUgTtlKH9r@zx2c4.com/> On Mon, Sep 12, 2022 at 11:48 AM Jason A. Donenfeld Jason@zx2c4.com wrote:
Ah another thing:
On Mon, Sep 12, 2022 at 11:45 AM Jason A. Donenfeld Jason@zx2c4.com wrote:
My machine went through three changes I know about between the threshold of "not crashing" and "crashing":
- Upgraded to 5.19 and then 6.0-rc1.
- I used my laptop on batteries for a prolonged period of time for the first time in a while.
- I updated KDE, whose power management UI elements may or may not make frequent calls to this subsystem to update some visual representation.
- Updated my BIOS.
GASP! The plot thickens.
It appears that the BIOS update I applied has been removed from https://pcsupport.lenovo.com/fr/en/downloads/ds551052-bios-update-utility-bo... https://pcsupport.lenovo.com/fr/en/downloads/ds551052-bios-update-utility-bootable-cd-for-windows-10-64-bit-and-linux-thinkpad-p1-gen-4-x1-extreme-gen-4 and now it only shows the 1.16 version. I updated from 1.16 to 1.18.
The missing release notes are still online if you futz with the URL: https://download.lenovo.com/pccbbs/mobiles/n40ur14w.txt https://download.lenovo.com/pccbbs/mobiles/n40ur14w.txt https://download.lenovo.com/pccbbs/mobiles/n40ur15w.txt https://download.lenovo.com/pccbbs/mobiles/n40ur15w.txt
One of the items for 1.17 says:
- (Fix) Fixed an issue where it took a long time to update the battery FW.
So maybe something was happening here...
I'm CC'ing Mark from Lenovo to see if he has any insight as to why this BIOS update was pulled.
Maybe the battery was appearing and disappearing rapidly. If that's correct, then it'd indicate that this bandaid patch is *wrong* and what actually is needed is some kind of reference counting or RCU around that sysfs interface (and maybe others).
Jason
Hi Jason,
I'll have to check with the FW team but looking at the internal notes I think the FW was pulled because of a graphics display regression. Version 36W was fixing a brightness control issue in discrete mode and 37W (not yet released) is fixing external display - so my guess is something about the fix in 36W has a side effect
More interesting is the EC FW updates. There isn't a new version posted but there are fixes in the previous version (EC 33W) for a fix for a 'suspected EC-Battery communication transaction failure'. Is that potentially related to this patch in some way? I can go and ask for more details if we think it's related. I'll also see if I can repro on my P1G4 - but I hadn't seen any other reports so it might be HW specific.
Can you confirm which FW you have from the BIOS setup screen (F1 during early boot)? BIOS and EC please.
Mark