wifi: iwlwifi: mvm: fix hibernation

Fast resume is a feature that was recently introduced to speed up the
resume time. It basically keeps the firmware alive while the system
is suspended and that avoids starting again the whole device.

This flow can't work for hibernation, since when the system boots,
before the frozen image is loaded, the kernel may touch the device. As a
result, we can't assume the device is in the exact same state as before
the hibernation.

Detect that we are resuming from hibernation through the PCI device and
forbid the fast resume flow. We also need to shut down the device
cleanly when that happens.

In addition, in case the device is power gated during S3, we won't be
able to keep the device alive. Detect this situation with BE200 at least
with the help of the CSR_FUNC_SCRATCH register and reset the device upon
resume if it was power gated during S3.

Fixes: e8bb19c1d590 ("wifi: iwlwifi: support fast resume")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20240825191257.24eb3b19e74f.I3837810318dbef0a0a773cf4c4fcf89cdc6fdbd3@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-op-mode.h b/drivers/net/wireless/intel/iwlwifi/iwl-op-mode.h
index 595fa6ddf084..8ef5ed2db051 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-op-mode.h
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-op-mode.h
@@ -85,6 +85,10 @@ struct iwl_cfg;
  *	May sleep
  * @wimax_active: invoked when WiMax becomes active. May sleep
  * @time_point: called when transport layer wants to collect debug data
+ * @device_powered_off: called upon resume from hibernation but not only.
+ *	Op_mode needs to reset its internal state because the device did not
+ *	survive the system state transition. The firmware is no longer running,
+ *	etc...
  */
 struct iwl_op_mode_ops {
 	struct iwl_op_mode *(*start)(struct iwl_trans *trans,
@@ -107,6 +111,7 @@ struct iwl_op_mode_ops {
 	void (*time_point)(struct iwl_op_mode *op_mode,
 			   enum iwl_fw_ini_time_point tp_id,
 			   union iwl_dbg_tlv_tp_data *tp_data);
+	void (*device_powered_off)(struct iwl_op_mode *op_mode);
 };
 
 int iwl_opmode_register(const char *name, const struct iwl_op_mode_ops *ops);
@@ -204,4 +209,11 @@ static inline void iwl_op_mode_time_point(struct iwl_op_mode *op_mode,
 	op_mode->ops->time_point(op_mode, tp_id, tp_data);
 }
 
+static inline void iwl_op_mode_device_powered_off(struct iwl_op_mode *op_mode)
+{
+	if (!op_mode || !op_mode->ops || !op_mode->ops->device_powered_off)
+		return;
+	op_mode->ops->device_powered_off(op_mode);
+}
+
 #endif /* __iwl_op_mode_h__ */