From 9d39e5bad76a8830a8fa0c03cadc1e36ce2ec2ef Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Tue, 19 Apr 2011 07:38:23 -0700
Subject: [PATCH] iwlagn: avoid hangs when restarting device
If a device error happens while the uCode is
being loaded or initialised, we will attempt
to restart the device (which will likely fail
again, but that's not the issue here). During
this new restart, we turn off the device, but
as the uCode failed to initialise it already
is turned off. As a consequence, grabbing NIC
access will fail and cause excessive messages
and hangs.
To fix this issue, introduce a new status bit
and only attempt to reprogram the device when
it isn't already disabled.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
---
drivers/net/wireless/iwlwifi/iwl-agn-lib.c | 21 +++++++++++++++------
drivers/net/wireless/iwlwifi/iwl-core.c | 4 ++++
drivers/net/wireless/iwlwifi/iwl-core.h | 1 +
3 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index e202a40cbcb7..75e1035330be 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -2363,12 +2363,21 @@ void iwlagn_stop_device(struct iwl_priv *priv)
/* device going down, Stop using ICT table */
iwl_disable_ict(priv);
- iwlagn_txq_ctx_stop(priv);
- iwlagn_rxq_stop(priv);
-
- /* Power-down device's busmaster DMA clocks */
- iwl_write_prph(priv, APMG_CLK_DIS_REG, APMG_CLK_VAL_DMA_CLK_RQT);
- udelay(5);
+ /*
+ * If a HW restart happens during firmware loading,
+ * then the firmware loading might call this function
+ * and later it might be called again due to the
+ * restart. So don't process again if the device is
+ * already dead.
+ */
+ if (test_bit(STATUS_DEVICE_ENABLED, &priv->status)) {
+ iwlagn_txq_ctx_stop(priv);
+ iwlagn_rxq_stop(priv);
+
+ /* Power-down device's busmaster DMA clocks */
+ iwl_write_prph(priv, APMG_CLK_DIS_REG, APMG_CLK_VAL_DMA_CLK_RQT);
+ udelay(5);
+ }
/* Make sure (redundant) we've released our request to stay awake */
iwl_clear_bit(priv, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index af72fd51ea74..66da1dec982c 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -995,6 +995,8 @@ void iwl_apm_stop(struct iwl_priv *priv)
{
IWL_DEBUG_INFO(priv, "Stop card, put in low power state\n");
+ clear_bit(STATUS_DEVICE_ENABLED, &priv->status);
+
/* Stop device's DMA activity */
iwl_apm_stop_master(priv);
@@ -1109,6 +1111,8 @@ int iwl_apm_init(struct iwl_priv *priv)
iwl_set_bits_prph(priv, APMG_PCIDEV_STT_REG,
APMG_PCIDEV_STT_VAL_L1_ACT_DIS);
+ set_bit(STATUS_DEVICE_ENABLED, &priv->status);
+
out:
return ret;
}
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index 32a990ff09ae..6226e3d9f101 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -592,6 +592,7 @@ void iwlcore_free_geos(struct iwl_priv *priv);
#define STATUS_SCAN_HW 15
#define STATUS_POWER_PMI 16
#define STATUS_FW_ERROR 17
+#define STATUS_DEVICE_ENABLED 18
static inline int iwl_is_ready(struct iwl_priv *priv)
--
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