Public bug reported: [Impact] Some platforms may keep USB power in S3/S4/S5, so Realtek 8821C retains its firmware even with a cold boot.
[Fix] Use vendor command to drop firmware if the version is old. [Test case] Use dmesg to check if new firmware is loaded. With the patch applied, we can find new firmware is loaded. [Where problems could occur] There's a 200ms delay which can slow down when BT controller is opened by userspace first time. ** Affects: linux (Ubuntu) Importance: Medium Status: Confirmed ** Affects: linux-oem-5.6 (Ubuntu) Importance: Undecided Status: Invalid ** Affects: linux (Ubuntu Focal) Importance: Medium Status: Confirmed ** Affects: linux-oem-5.6 (Ubuntu Focal) Importance: Medium Status: Confirmed ** Affects: linux (Ubuntu Groovy) Importance: Medium Status: Confirmed ** Affects: linux-oem-5.6 (Ubuntu Groovy) Importance: Undecided Status: Invalid ** Also affects: linux (Ubuntu Groovy) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Focal) Importance: Undecided Status: New ** Also affects: linux-oem-5.6 (Ubuntu) Importance: Undecided Status: New ** Changed in: linux-oem-5.6 (Ubuntu Groovy) Status: New => Invalid ** Changed in: linux-oem-5.6 (Ubuntu) Status: New => Invalid ** Changed in: linux (Ubuntu) Status: New => Confirmed ** Changed in: linux (Ubuntu Focal) Status: New => Confirmed ** Changed in: linux-oem-5.6 (Ubuntu Focal) Status: New => Confirmed ** Changed in: linux (Ubuntu Groovy) Status: New => Confirmed ** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Focal) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Groovy) Importance: Undecided => Medium ** Changed in: linux-oem-5.6 (Ubuntu Focal) Importance: Undecided => Medium -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1904221 Title: Ask 8821C Bluetooth controller to drop old firmware Status in linux package in Ubuntu: Confirmed Status in linux-oem-5.6 package in Ubuntu: Invalid Status in linux source package in Focal: Confirmed Status in linux-oem-5.6 source package in Focal: Confirmed Status in linux source package in Groovy: Confirmed Status in linux-oem-5.6 source package in Groovy: Invalid Bug description: [Impact] Some platforms may keep USB power in S3/S4/S5, so Realtek 8821C retains its firmware even with a cold boot. [Fix] Use vendor command to drop firmware if the version is old. [Test case] Use dmesg to check if new firmware is loaded. With the patch applied, we can find new firmware is loaded. [Where problems could occur] There's a 200ms delay which can slow down when BT controller is opened by userspace first time. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1904221/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp