On 3/4/2024 6:13 PM, Baochen Qiang wrote: > Now that all infrastructure is in place and ath11k is fixed to handle all the > corner cases, power down the ath11k firmware during suspend and power it back > up during resume. This fixes the problem when using hibernation with ath11k PCI > devices. > > For suspend, two conditions needs to be satisfied: > 1. since MHI channel unprepare would be done in late suspend stage, > ath11k needs to get all QMI-dependent things done before that stage. > 2. and because unprepare MHI channels requires a working MHI stack, > ath11k is not allowed to call mhi_power_down() until that finishes. > So the original suspend callback is separated into two parts: the first part > handles all QMI-dependent things in suspend callback; while the second part > powers down MHI in suspend_late callback. This is valid because kernel calls > ath11k's suspend callback before all suspend_late callbacks, making the first > condition happy. And because MHI devices are children of ath11k device > (ab->dev), kernel guarantees that ath11k's suspend_late callback is called > after QRTR's suspend_late callback, this satisfies the second condition. > > Above analysis also applies to resume process. so the original resume > callback is separated into two parts: the first part powers up MHI stack > in resume_early callback, this guarantees MHI stack is working when > QRTR tries to prepare MHI channels (kernel calls QRTR's resume_early callback > after ath11k's resume_early callback, due to the child-father relationship); > the second part waits for the completion of restart, which won't fail now > since MHI channels are ready for use by QMI. > > Another notable change is in power down path, we tell mhi_power_down() to not > to destroy MHI devices, making it possible for QRTR to help unprepare/prepare > MHI channels, and finally get us rid of the probe-defer issue when resume. > > Also change related code due to interface changes. > > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30 > > Tested-by: Takashi Iwai <tiwai@xxxxxxx> > Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx> Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
