> On 18-Nov-2021, at 12:31 AM, Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote: > > Hi Orlando, > >>> 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. > > Regards > > Marcel >
