Hi, this is your Linux kernel regression tracker speaking again. On 19.11.21 17:59, Aditya Garg wrote: >> On 18-Nov-2021, at 12:31 AM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote: >>>> 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? >>> >>> I think we should be able to quirk based off the acpi _CID "apple-uart-blth" >>> or _HID "BCM2E7C". Marcel suggested quirking based of the acpi table here >>> https://lore.kernel.org/linux-bluetooth/1D2217A9-EA73-4D93-8D0B-5BC2718D4788@xxxxxxxxxxxx/ >>> >>> This would catch some unaffected Macs, but they don't support the LE Read >>> Transmit Power command anyway (the affected macs were released after it >>> was added to the Bluetooth spec, while the unaffected Macs were released >>> before it was added to the spec, and thus don't support it). >>> >>> I'm not sure how to go about applying a quirk based off this, there are >>> quirks in drivers/bluetooth/hci_bcm.c (no_early_set_baudrate and >>> drive_rts_on_open), but they don't seem to be based off acpi ids. >>> >>> It might be simpler to make it ignore the Unknown Command error, like >>> in this patch https://lore.kernel.org/linux-bluetooth/CABBYNZLjSfcG_KqTEbL6NOSvHhA5-b1t_S=3FQP4=GwW21kuzg@xxxxxxxxxxxxxx/ >>> however that only applies on bluetooth-next and needed the status it >>> checks for to be -56, not 0x01. >> >> so we abstain from try-and-error sending of commands. The Bluetooth spec >> has a list of supported commands that a host can query for a reason. This >> is really broken behavior of the controller and needs to be pointed out as >> such. > Well all I can do is provide you any logs or information I can. But we do really wish to get this regression fixed soon. >> >> The question is just how we quirk it. This thread once again looks stalled and smells a lot like "everyone agrees that his should be fixed, but afaics nobody submitted a fix or committed to work on one". Please speak up if my impression is wrong, as this is a regression and thus needs to be fixed, ideally quickly. Part of my job is to make that happen and thus remind developers and maintainers about this until we have a fix. Ciao, Thorsten #regzbot title bluetooth: "Query LE tx power on startup" broke Bluetooth on MacBookPro16,1 #regzbot poke
