dell-uart-backlight fails to communicate with the scalar IC somtimes.
Affects | Status | Importance | Assigned to | Milestone | ||
---|---|---|---|---|---|---|
HWE Next |
New
|
Undecided
|
Unassigned | |||
linux (Ubuntu) | Status tracked in Mantic | |||||
Jammy |
Invalid
|
Undecided
|
Unassigned | |||
Mantic |
In Progress
|
Undecided
|
AceLan Kao | |||
linux-oem-6.5 (Ubuntu) | Status tracked in Mantic | |||||
Jammy |
Fix Released
|
Undecided
|
AceLan Kao | |||
Mantic |
Invalid
|
Undecided
|
Unassigned |
Bug Description
[Impact]
Boots up the system and sometimes we can see below messages and that leads to backlight driver doesn't get loaded.
[ 86.424880] dell_uart_
[ 86.603936] [7439] dell_uart_
[ 87.596047] dell_uart_
[ 87.775209] [7439] dell_uart_
[Fix]
After applying the patch below, it seems that the read() command may fail to receive a response, even when increasing the retry times. It never gets a response when it fails.
fbf84fb368923 ("UBUNTU: SAUCE: platform/x86: dell-uart-
To fix this, try adding a small delay after the write() function as a workaround.
[Test case]
1. Add dell_uart_
2. Boots up the system and check dmesg
3. Make sure there is no dell_uart_backlight rx NULL message in dmesg
4. Try to unload/reload dell_uart_backlight couple times and check dmesg again
[Where problems could occur]
sleep for 1ms is pretty short that it's not possible to lead to messages loss.
Changed in linux (Ubuntu Jammy): | |
status: | New → Invalid |
Changed in linux-oem-6.5 (Ubuntu Mantic): | |
status: | New → Invalid |
Changed in linux (Ubuntu Mantic): | |
assignee: | nobody → AceLan Kao (acelankao) |
Changed in linux-oem-6.5 (Ubuntu Jammy): | |
assignee: | nobody → AceLan Kao (acelankao) |
Changed in linux (Ubuntu Mantic): | |
status: | New → In Progress |
Changed in linux-oem-6.5 (Ubuntu Jammy): | |
status: | New → In Progress |
tags: | added: oem-priority originate-from-2033577 somerville |
description: | updated |
Changed in linux-oem-6.5 (Ubuntu Jammy): | |
status: | In Progress → Fix Committed |
tags: |
added: verification-done-jammy-linux-oem-6.5 removed: verification-needed-jammy-linux-oem-6.5 |
This bug is awaiting verification that the linux-oem- 6.5/6.5. 0-1004. 4 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- jammy-linux- oem-6.5' to 'verification- done-jammy- linux-oem- 6.5'. If the problem still exists, change the tag 'verification- needed- jammy-linux- oem-6.5' to 'verification- failed- jammy-linux- oem-6.5' .
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!