Please add support for Qualcomm IPC Router in 5.4 focal kernel

[Alfonso Sanchez-Beato]

The modemmanager debian package in focal was recently upgraded to 1.18 (the jammy version was backported - see LP: #1965901). This version has broken some Qualcomm modems as it start to require the Qualcomm IPC Router for them, which drivers are not enabled in Ubuntu kernel 5.4. To fix this we need these options enabled in the focal kernel:

CONFIG_QRTR=m
CONFIG_QRTR_SMD=m
CONFIG_QRTR_TUN=m
CONFIG_QRTR_MHI=m

The options are already enabled in more modern Ubuntu kernel, i.e. 5.17.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1998194

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Alfonso Sanchez-Beato (alfonsosanchezbeato)]

Changing to confirmed as I cannot run the apport command in the system where this was found.

[Kuba Pawlak (kuba-t-pawlak)]

In 5.4 Focal CONFIG_QRTR depends on ARCH_QCOM, which is a platform config that enables ARMv8 based Qualcomm chipsets, so it can not be enabled on amd64. Also CONFIG_QRTR_MHI is not present in 5.4, which means that the implementation is incomplete with respect to what modemmanager is expecting.

In later releases like Jammy, CONFIG_QRTR has no dependency on ARCH_QCOM and therefore is enabled on amd64. All QRTR modules are also there.

Enabling QRTR in 5.4 kernel would require backporting patches to remove its dependence on ARCH_QCOM and to add MHI module.
It is suggested to check modulemanager implementation whether hard requirement on QRTR modules can be skipped on amd64.

[You-Sheng Yang (vicamo)]

In src/mm-context.c, it appears that can be disabled with an argument:

262 #if defined WITH_QRTR
263 {
264 "test-no-qrtr", 0, 0, G_OPTION_ARG_NONE, &test_no_qrtr,
265 "Run without qrtr support even if available",
266 NULL
267 },
268 #endif

And probably all one has to do is to test if qrtr is actually supported by the running kernel:

330 #if defined WITH_QRTR
331 gboolean
332 mm_context_get_test_no_qrtr (void)
333 {
334 return test_no_qrtr;
335 }
336 #endif

[Rex Tsai (chihchun)]

Removed oem-priority, confirmed this is not a certified device, and it's not in the support scope.
However, this is a regression that breaks previous supported hardware in mm and kernel.