Hi! Realtek will send a patch to fix this issue. BRs, Max > -----Original Message----- > From: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> > Sent: Wednesday, October 4, 2023 7:46 PM > To: Max Chou <max.chou@xxxxxxxxxxx> > Cc: Bagas Sanjaya <bagasdotme@xxxxxxxxx>; Hilda Wu > <hildawu@xxxxxxxxxxx>; alex_lu@xxxxxxxxxxxxxx; Luiz Augusto von Dentz > <luiz.von.dentz@xxxxxxxxx>; Marcel Holtmann <marcel@xxxxxxxxxxxx>; > Johan Hedberg <johan.hedberg@xxxxxxxxx>; Juerg Haefliger > <juerg.haefliger@xxxxxxxxxxxxx>; Linux Bluetooth > <linux-bluetooth@xxxxxxxxxxxxxxx>; Thorsten Leemhuis <linux@xxxxxxxxxxxxx>; > Linux Regressions <regressions@xxxxxxxxxxxxxxx>; Linux Kernel Mailing List > <linux-kernel@xxxxxxxxxxxxxxx> > Subject: Re: Regression: devcoredump patch broke Realtek usb bluetooth > adapter > > > External mail. > > > > On Wed, Oct 04, 2023 at 07:28:45AM +0000, Max Chou wrote: > > Hi! Kirill, > > I guess the root cause is as below. > > === > > static int btrtl_register_devcoredump_support(struct hci_dev *hdev) { > > int err; > > > > err = hci_devcd_register(hdev, btrtl_coredump, btrtl_dmp_hdr, > > NULL); > > > > return err; > > } > > === > > If CONFIG_DEV_COREDUMP is not enabled, it would return -EOPNOTSUPP > for hci_devcd_register(). > > Unfortunately, btrtl_register_devcoredump_support() will return it. > > Finally, -EOPNOSTUPP will be returned for btrtl_setup_realtek(). > > > > Could you have the following workaround for the root cause checked? > > Please share dmesg as well. Thanks, > > Yes. It works and I see > > [ 3.640539] Bluetooth: hci0: RTL: btrtl_register_devcoredump_support(): > err = -95 > > in dmesg. -EOPNOTSUPP indeed. > > -- > Kiryl Shutsemau / Kirill A. Shutemov