CHROMIUM: iwl7000: sdio: avoid read/write operations if the bus is dead

Recovery takes too much time if the bus is dead (each timeout
is 2000ms, etc.).
try avoiding it by setting a flag when the bus is dead, and avoid
any bus access until recovery.

There still might be significant delays caused by implicit
mmc access (e.g. sdio_disable_func()), but at least avoid
the direct read/write operations.

Additionally, explicitly skip fw dump in this case, as it will
result in garbage data (and might take signifcant time)
--
TODO: are there valid failures?

Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
iwl7000-tree: b5e41377e07fe71bbb562ffb36057ffd93adacd8

drivers/net/wireless/iwl7000/iwlwifi/iwl-trans.h

@@ -412,6 +412,7 @@ enum iwl_d3_status {
  *	are sent
  * @STATUS_TRANS_IDLE: the trans is idle - general commands are not to be sent
  * @STATUS_TA_ACTIVE: target access is in progress
+ * @STATUS_TRANS_DEAD: trans is dead - avoid any read/write operation
  */
 enum iwl_trans_status {
 	STATUS_SYNC_HCMD_ACTIVE,
@@ -423,6 +424,7 @@ enum iwl_trans_status {
 	STATUS_TRANS_GOING_IDLE,
 	STATUS_TRANS_IDLE,
 	STATUS_TA_ACTIVE,
+	STATUS_TRANS_DEAD,
 };
 
 /**

drivers/net/wireless/iwl7000/iwlwifi/mvm/mac80211.c

@@ -1149,6 +1149,12 @@ void iwl_mvm_fw_error_dump(struct iwl_mvm *mvm)
 
 	lockdep_assert_held(&mvm->mutex);
 
+	/* there's no point in fw dump if the bus is dead */
+	if (test_bit(STATUS_TRANS_DEAD, &mvm->trans->status)) {
+		IWL_ERR(mvm, "Skip fw error dump since bus is dead\n");
+		return;
+	}
+
 	fw_error_dump = kzalloc(sizeof(*fw_error_dump), GFP_KERNEL);
 	if (!fw_error_dump)
 		return;