** Changed in: linux-oem-5.13 (Ubuntu Focal)
Status: Confirmed => Fix Committed
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-oem-5.10 in Ubuntu.
https://bugs.launchpad.net/bugs/1936682
Title:
Fix kernel panic caused by legacy devices on AMD platforms
Status in HWE Next:
New
Status in linux package in Ubuntu:
Confirmed
Status in linux-oem-5.10 package in Ubuntu:
Invalid
Status in linux-oem-5.13 package in Ubuntu:
Invalid
Status in linux source package in Focal:
Won't Fix
Status in linux-oem-5.10 source package in Focal:
Fix Committed
Status in linux-oem-5.13 source package in Focal:
Fix Committed
Status in linux source package in Hirsute:
Confirmed
Status in linux-oem-5.10 source package in Hirsute:
Invalid
Status in linux-oem-5.13 source package in Hirsute:
Invalid
Status in linux source package in Impish:
Confirmed
Status in linux-oem-5.10 source package in Impish:
Invalid
Status in linux-oem-5.13 source package in Impish:
Invalid
Bug description:
[Impact]
When a legacy device is only 32bit DMA capable and it's in the same
IOMMU group with iommu_v2 capable devices, the device in question will
be forced to use identity mapping and triggers kernel panic on DMA
operation because it can't do 64bit DMA.
[Fix]
Keep swiotlb enabled so legacy devices can do 64bit DMA. This is also
how Intel and ARM64 platforms deal with legacy devices.
[Test]
Boot an affected system. Kernel panic in Realtek WiFi driver's probe
routine.
After the patch is applied, the system can work normally.
[Where problems could occur]
The default swiotlb uses 64MB memory, so if the system doesn't have any
legacy device, there are 64MB ram less for the system to use.
To manage notifications about this bug go to:
https://bugs.launchpad.net/hwe-next/+bug/1936682/+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
