iwlwifi: mvm: don't send commands during suspend\resume transition

D3_CONFIG_CMD and D0I3_END_CMD should be the last\first
command upon suspend\resume correspondingly, otherwise,
FW will raise an assert (0x342).

There are firmware notifications that cause the driver to
send a command back to the firmware. If such a notification
is sent to the driver while the the driver prepares the
firmware for D3, operation, what is likely to happen is that
the handling of the notification will try to get the mutex
and will wait unil the driver finished configuring the
firmware for D3. Then the handling notification will get
the mutex and handle the notification which will lead to
the aforementioned ASSERT 342.

To avoid this, we need to prevent any command to be sent to
the firmware between the D3_CONFIG_CMD and the D0I3_END_CMD.
Check this in the utility layer that sends the host commands
and in the transport layer as well.
Flag the D3_CONFIG_CMD and the D0I3_END_CMD commands as
commands that must be sent even if the firmware has already
been configured for D3 operation.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210117164916.1935a993b471.I3192c93c030576ca16773c01b009c4d93610d6ea@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
index 563d12939854..2c741bc8a5c9 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/tx-gen2.c
@@ -358,6 +358,12 @@ int iwl_trans_pcie_gen2_send_hcmd(struct iwl_trans *trans,
 		return -ERFKILL;
 	}
 
+	if (unlikely(trans->system_pm_mode == IWL_PLAT_PM_MODE_D3 &&
+		     !(cmd->flags & CMD_SEND_IN_D3))) {
+		IWL_DEBUG_WOWLAN(trans, "Dropping CMD 0x%x: D3\n", cmd->id);
+		return -EHOSTDOWN;
+	}
+
 	if (cmd->flags & CMD_ASYNC) {
 		int ret;