Hi Guenter,
> [ Greg asked me to submit a report to regressions@, so here it is. ]
>
> The following error was observed on Chromebooks with MT8183 CPU
> (ASUS Chromebook Detachable CM3, HP Chromebook 11a, and others):
>
> [ 224.735198] Bluetooth: qca_setup() hci0: setting up ROME/QCA6390
> [ 225.205024] Bluetooth: qca_read_soc_version() hci0: QCA Product ID :0x00000008
> [ 225.205040] Bluetooth: qca_read_soc_version() hci0: QCA SOC Version :0x00000044
> [ 225.205045] Bluetooth: qca_read_soc_version() hci0: QCA ROM Version :0x00000302
> [ 225.205049] Bluetooth: qca_read_soc_version() hci0: QCA Patch Version:0x000003e8
> [ 225.205055] Bluetooth: qca_uart_setup() hci0: QCA controller version 0x00440302
> [ 225.205061] Bluetooth: qca_download_firmware() hci0: QCA Downloading qca/rampatch_00440302.bin
> [ 227.252653] Bluetooth: hci_cmd_timeout() hci0: command 0xfc00 tx timeout
> ...
> [ 223.604971] Bluetooth: qca_recv() hci0: Frame reassembly failed (-84)
> [ 223.605027] Bluetooth: qca_recv() hci0: Frame reassembly failed (-84)
> (repeated several times)
> ...
>
> The Bluetooth interface on those Chromebooks can not be enabled.
>
> Bisect suggests that upstream commit 0ea9fd001a14 ("Bluetooth: Shutdown
> controller after workqueues are flushed or cancelled") introduced the problem.
> Reverting it fixes the problem.
>
> The problem was also reported at [1] on a Mediatek Pumpkin board.
>
> As of this writing, the problem is still present in the upstream kernel
> as well as in all stable releases which include commit 0ea9fd001a14.
post it to the linux-bluetooth@vger mailing list. This is Qualcomm driver
specific and maybe they broke something. However there is an ongoing
discussion about your bi-sected commit regarding Mediatek Bluetooth device
where this seems to also have caused a problem.
Regards
Marcel
