On 17.11.21 10:26, Aditya Garg wrote: >> On 17-Nov-2021, at 12:55 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> On Wed, Nov 17, 2021 at 03:28:29AM +0000, Aditya Garg wrote: >>>> On 16-Nov-2021, at 2:56 PM, Thorsten Leemhuis <regressions@xxxxxxxxxxxxx> wrote: >>>> On 16.11.21 10:02, Orlando Chamberlain wrote: >>>>>> Bluetooth maintainers, what's the status here? The proposed patch is >>>>>> fixing a regression. It's not a recent one (it afaics was introduced in >>>>>> v5.11-rc1). Nevertheless it would be good to get this finally resolved. >>>>>> But this thread seems inactive for more than a week now. Or was progress >>>>>> made, but is only visible somewhere else? >>>>> >>>>> I think the best solution is getting broadcom to update their firmware, >>>>> I've just sent them a message through a form on their website, I couldn't >>>>> seem to get it to tell me "Your message has been sent", so it's possible >>>>> that it didn't submit (more likely I've sent the same message several times). >>>>> >>>>> If I hear back from them I'll send something here. >>>> >>>> Thx for that. But FWIW: from the point of the regression tracker that's >>>> not the best solution, as according to your report this is a regression. >>>> IOW: we deal with something that used to up to a certain kernel version >>>> and was broken by a change to the kernel. That is something frown upon >>>> in Linux kernel development, hence changes introducing regression are >>>> often quickly reverted, if they can't get fixed by follow up change quickly. >>>> >>>> That sentence has two "quickly", as we want to prevent more people >>>> running into the issue, resulting in a loss of trust. But that's what >>>> will happen if we wait for a firmware update to get developed, tested, >>>> published, and rolled out. And even then we can't expect users to have >>>> the latest firmware installed when they switch to a new kernel. >>>> >>>> Hence the best solution *afaics* might be: fix this in the kernel >>>> somehow now with a workaround; once the firmware update is out, change >>>> the kernel again to only apply the workaround if the old firmware is in use. >>> I have an idea. Can we make LE Read Transmit Power as a module parameter and users can turn it off if it is causing trouble. I have a patch for the same but haven't tested it yet. >> >> Module parameters are for the 1990's, please never add new ones as they >> modify code, not data, and you want to do something like this on a >> per-device basis, not on "all devices in the system", right? > > Exactly. Since the issue affects only a few Macs and not all devices. > In fact I have spotted just 2 Macs yet affected with this issue. When Greg said "per-device basis", he afaics meant: per-device in a system, as a module parameter would also affect a second bluetooth controller if there was one (say one connected via USB) -- and that shouldn't happen. And FWIW: it's still a regression if something that used to work suddenly requires a module parameter to get working. So if this just affects two macs, why can't the fix be realized as a quirk that is only enabled on those two systems? Or are they impossible to detect clearly via DMI data or something like that? Ciao, Thorsten
