Baochen Qiang [off-list ref] writes:
On 2/29/2024 6:12 PM, Manivannan Sadhasivam wrote:
quoted
On Wed, Feb 28, 2024 at 10:22:41AM +0800, Baochen Qiang wrote:
quoted
ath11k fails to resume:
ath11k_pci 0000:06:00.0: timeout while waiting for restart complete
This happens because when calling mhi_sync_power_up() the MHI subsystem
eventually calls device_add() from mhi_create_devices() but the device
creation is deferred:
mhi mhi0_IPCR: Driver qcom_mhi_qrtr force probe deferral
The reason for deferring device creation is explained in dpm_prepare():
/*
* It is unsafe if probing of devices will happen during suspend or
* hibernation and system behavior will be unpredictable in this case.
* So, let's prohibit device's probing here and defer their probes
* instead. The normal behavior will be restored in dpm_complete().
*/
Because the device probe is deferred, the qcom_mhi_qrtr_probe() is not
called and thus MHI channels are not prepared:
So what this means that QRTR is not delivering messages and the QMI connection
is not working between ath11k and the firmware, resulting a failure in firmware
initialization.
To fix this add new function mhi_power_down_keep_dev() which doesn't destroy
the devices for channels during power down. This way we avoid probe defer issue
and finally can get ath11k hibernation working with the following patches.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
Signed-off-by: Kalle Valo <redacted>
Did Kalle co-author this patch? If so, his Co-developed-by tag should
be added.
Hmm, I'm not sure... I would like Kalle's thoughts on this.
IIRC I did only some simple cleanup before submitting the patch so I
don't think Co-developed-by is justified. I'm also fine with removing my
Signed-off-by.
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