iwlwifi: pcie: lock start_hw / start_fw / stop_device
This allows to ensure that we don't have races between them.
A user reported that stop_device was called twice upon
rfkill interrupt after suspend. When the interrupts are
enabled, and right after when we directly check the rfkill
state.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 43ae658..23f2824 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -982,13 +982,25 @@
static int iwl_trans_pcie_start_fw(struct iwl_trans *trans,
const struct fw_img *fw, bool run_in_rfkill)
{
- int ret;
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
bool hw_rfkill;
+ int ret;
+
+ mutex_lock(&trans_pcie->mutex);
+
+ /* Someone called stop_device, don't try to start_fw */
+ if (trans_pcie->is_down) {
+ IWL_WARN(trans,
+ "Can't start_fw since the HW hasn't been started\n");
+ ret = EIO;
+ goto out;
+ }
/* This may fail if AMT took ownership of the device */
if (iwl_pcie_prepare_card_hw(trans)) {
IWL_WARN(trans, "Exit HW not ready\n");
- return -EIO;
+ ret = -EIO;
+ goto out;
}
iwl_enable_rfkill_int(trans);
@@ -1000,15 +1012,17 @@
else
clear_bit(STATUS_RFKILL, &trans->status);
iwl_trans_pcie_rf_kill(trans, hw_rfkill);
- if (hw_rfkill && !run_in_rfkill)
- return -ERFKILL;
+ if (hw_rfkill && !run_in_rfkill) {
+ ret = -ERFKILL;
+ goto out;
+ }
iwl_write32(trans, CSR_INT, 0xFFFFFFFF);
ret = iwl_pcie_nic_init(trans);
if (ret) {
IWL_ERR(trans, "Unable to init nic\n");
- return ret;
+ goto out;
}
/* make sure rfkill handshake bits are cleared */
@@ -1026,9 +1040,13 @@
/* Load the given image to the HW */
if (trans->cfg->device_family == IWL_DEVICE_FAMILY_8000)
- return iwl_pcie_load_given_ucode_8000(trans, fw);
+ ret = iwl_pcie_load_given_ucode_8000(trans, fw);
else
- return iwl_pcie_load_given_ucode(trans, fw);
+ ret = iwl_pcie_load_given_ucode(trans, fw);
+
+out:
+ mutex_unlock(&trans_pcie->mutex);
+ return ret;
}
static void iwl_trans_pcie_fw_alive(struct iwl_trans *trans, u32 scd_addr)
@@ -1037,11 +1055,18 @@
iwl_pcie_tx_start(trans, scd_addr);
}
-static void iwl_trans_pcie_stop_device(struct iwl_trans *trans, bool low_power)
+static void _iwl_trans_pcie_stop_device(struct iwl_trans *trans, bool low_power)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
bool hw_rfkill, was_hw_rfkill;
+ lockdep_assert_held(&trans_pcie->mutex);
+
+ if (trans_pcie->is_down)
+ return;
+
+ trans_pcie->is_down = true;
+
was_hw_rfkill = iwl_is_rfkill_set(trans);
/* tell the device to stop sending interrupts */
@@ -1131,10 +1156,24 @@
iwl_pcie_prepare_card_hw(trans);
}
+static void iwl_trans_pcie_stop_device(struct iwl_trans *trans, bool low_power)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+
+ mutex_lock(&trans_pcie->mutex);
+ _iwl_trans_pcie_stop_device(trans, low_power);
+ mutex_unlock(&trans_pcie->mutex);
+}
+
void iwl_trans_pcie_rf_kill(struct iwl_trans *trans, bool state)
{
+ struct iwl_trans_pcie __maybe_unused *trans_pcie =
+ IWL_TRANS_GET_PCIE_TRANS(trans);
+
+ lockdep_assert_held(&trans_pcie->mutex);
+
if (iwl_op_mode_hw_rf_kill(trans->op_mode, state))
- iwl_trans_pcie_stop_device(trans, true);
+ _iwl_trans_pcie_stop_device(trans, true);
}
static void iwl_trans_pcie_d3_suspend(struct iwl_trans *trans, bool test)
@@ -1219,11 +1258,14 @@
return 0;
}
-static int iwl_trans_pcie_start_hw(struct iwl_trans *trans, bool low_power)
+static int _iwl_trans_pcie_start_hw(struct iwl_trans *trans, bool low_power)
{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
bool hw_rfkill;
int err;
+ lockdep_assert_held(&trans_pcie->mutex);
+
err = iwl_pcie_prepare_card_hw(trans);
if (err) {
IWL_ERR(trans, "Error while preparing HW: %d\n", err);
@@ -1240,20 +1282,38 @@
/* From now on, the op_mode will be kept updated about RF kill state */
iwl_enable_rfkill_int(trans);
+ /* Set is_down to false here so that...*/
+ trans_pcie->is_down = false;
+
hw_rfkill = iwl_is_rfkill_set(trans);
if (hw_rfkill)
set_bit(STATUS_RFKILL, &trans->status);
else
clear_bit(STATUS_RFKILL, &trans->status);
+ /* ... rfkill can call stop_device and set it false if needed */
iwl_trans_pcie_rf_kill(trans, hw_rfkill);
return 0;
}
+static int iwl_trans_pcie_start_hw(struct iwl_trans *trans, bool low_power)
+{
+ struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ int ret;
+
+ mutex_lock(&trans_pcie->mutex);
+ ret = _iwl_trans_pcie_start_hw(trans, low_power);
+ mutex_unlock(&trans_pcie->mutex);
+
+ return ret;
+}
+
static void iwl_trans_pcie_op_mode_leave(struct iwl_trans *trans)
{
struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
+ mutex_lock(&trans_pcie->mutex);
+
/* disable interrupts - don't enable HW RF kill interrupt */
spin_lock(&trans_pcie->irq_lock);
iwl_disable_interrupts(trans);
@@ -1266,6 +1326,7 @@
spin_unlock(&trans_pcie->irq_lock);
iwl_pcie_disable_ict(trans);
+ mutex_unlock(&trans_pcie->mutex);
}
static void iwl_trans_pcie_write8(struct iwl_trans *trans, u32 ofs, u8 val)
@@ -2472,6 +2533,7 @@
spin_lock_init(&trans_pcie->irq_lock);
spin_lock_init(&trans_pcie->reg_lock);
spin_lock_init(&trans_pcie->ref_lock);
+ mutex_init(&trans_pcie->mutex);
init_waitqueue_head(&trans_pcie->ucode_write_waitq);
err = pci_enable_device(pdev);