[PATCH] iwlwifi: reset card during probe

[y at redhat.com]

RHBZ#557084 

To ensure that card is in a sane state during probe we add a reset call.
This change was prompted by users of kdump who was not able to bring up the
wireless driver in the kdump kernel. The problem here was that the primary
kernel, which is not running at the time, left the wireless card up and
running. When the kdump kernel starts it is thus possible to immediately
receive interrupts from firmware after registering interrupt, but without
being ready to deal with interrupts from firmware yet.

Reported-by: Stanislaw Gruszka <sgruszka at redhat.com>
Signed-off-by: Reinette Chatre <reinette.chatre at intel.com>
Signed-off-by: Stanislaw Gruszka <sgruszka at redhat.com>
---
 drivers/net/wireless/iwlwifi/iwl-agn.c      |    8 ++++++++
 drivers/net/wireless/iwlwifi/iwl3945-base.c |    7 +++++++
 2 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 921dc4a..1661f3c 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -2976,6 +2976,14 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 * we should init now
 	 */
 	spin_lock_init(&priv->reg_lock);
+
+	/*
+	 * stop and reset the on-board processor just in case it is in a
+	 * strange state ... like being left stranded by a primary kernel
+	 * and this is now the kdump kernel trying to start up
+	 */
+	iwl_write32(priv, CSR_RESET, CSR_RESET_REG_FLAG_NEVO_RESET);
+
 	iwl_hw_detect(priv);
 	IWL_INFO(priv, "Detected Intel Wireless WiFi Link %s REV=0x%X\n",
 		priv->cfg->name, priv->hw_rev);
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 5f26c93..3726b01 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -4032,6 +4032,13 @@ static int iwl3945_pci_probe(struct pci_dev *pdev, const struct pci_device_id *e
 	IWL_INFO(priv, "Detected Intel Wireless WiFi Link %s\n",
 		priv->cfg->name);
 
+	/*
+	 * stop and reset the on-board processor just in case it is in a
+	 * strange state ... like being left stranded by a primary kernel
+	 * and this is now the kdump kernel trying to start up
+	 */
+	iwl_write32(priv, CSR_RESET, CSR_RESET_REG_FLAG_NEVO_RESET);
+
 	/***********************
 	 * 7. Setup Services
 	 * ********************/
-- 
1.6.2.5