Joonwoo Park wrote:
2008/1/11, Chatre, Reinette <reinette.chatre@xxxxxxxxx>:
On Thursday, January 10, 2008 5:25 PM, Joonwoo Park wrote:
What modification are you considering?
Roughly, I'm considering make synchronize_irq() be moved into
iwl_disable_interrupts() and fix iwl_irq_tasket not to call
iwl_disable_interrupts with irq disabled.
For now iwl_irq_tasklet calls iwl_disable_interrupts() with local irq disabled.
like this:
static void iwl_irq_tasklet(struct iwl_priv *priv)
{
...
spin_lock_irqsave(&priv->lock, flags);
...
/* Now service all interrupt bits discovered above. */
if (inta & CSR_INT_BIT_HW_ERR) {
IWL_ERROR("Microcode HW error detected. Restarting.\n");
/* Tell the device to stop sending interrupts */
iwl_disable_interrupts(priv);
...
spin_unlock_irqrestore(&priv->lock, flags);
return;
}
After disabling interrupts, it's possible irq & tasklet is pending or running
This patch eleminates races for down iwlwifi
Since synchronize_irq can introduce iwl_irq_tasklet, tasklet_kill
should be called after doing synchronize_irq
To avoid races between iwl_synchronize_irq and iwl_irq_tasklet STATUS_INT_ENABLED
flag is needed.
Signed-off-by: Joonwoo Park <joonwpark81@xxxxxxxxx>
---
drivers/net/wireless/iwlwifi/iwl3945-base.c | 33 ++++++++++++++++++++++-----
1 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 6e20725..f98cd4f 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -4405,6 +4405,14 @@ static void iwl_print_rx_config_cmd(struct iwl_rxon_cmd *rxon)
}
#endif
+static void iwl_synchronize_interrupts(struct iwl_priv *priv)
+{
+ synchronize_irq(priv->pci_dev->irq);
+ /* synchornize_irq introduces irq_tasklet,
+ * tasklet_kill should be called after doing synchronize_irq */
+ tasklet_kill(&priv->irq_tasklet);
+}
+
static void iwl_enable_interrupts(struct iwl_priv *priv)
{
IWL_DEBUG_ISR("Enabling interrupts\n");
@@ -4413,7 +4421,7 @@ static void iwl_enable_interrupts(struct iwl_priv *priv)
iwl_flush32(priv, CSR_INT_MASK);
}
-static inline void iwl_disable_interrupts(struct iwl_priv *priv)
+static inline void __iwl_disable_interrupts(struct iwl_priv *priv)
{
clear_bit(STATUS_INT_ENABLED, &priv->status);
@@ -4427,6 +4435,13 @@ static inline void iwl_disable_interrupts(struct iwl_priv *priv)
iwl_flush32(priv, CSR_INT);
iwl_write32(priv, CSR_FH_INT_STATUS, 0xffffffff);
iwl_flush32(priv, CSR_FH_INT_STATUS);
+}
+
+static inline void iwl_disable_interrupts(struct iwl_priv *priv)
+{
+ __iwl_disable_interrupts(priv);
+
+ iwl_synchronize_interrupts(priv);
IWL_DEBUG_ISR("Disabled interrupts\n");
}
@@ -4708,7 +4723,8 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
IWL_ERROR("Microcode HW error detected. Restarting.\n");
/* Tell the device to stop sending interrupts */
- iwl_disable_interrupts(priv);
+ __iwl_disable_interrupts(priv);
+ IWL_DEBUG_ISR("Disabled interrupts\n");
iwl_irq_handle_error(priv);
@@ -4814,8 +4830,11 @@ static void iwl_irq_tasklet(struct iwl_priv *priv)
IWL_WARNING(" with FH_INT = 0x%08x\n", inta_fh);
}
- /* Re-enable all interrupts */
- iwl_enable_interrupts(priv);
+ /* To avoid race when device goes down,
+ * it should be discarded to enable interrupts */
+ if (test_bit(STATUS_INT_ENABLED, &priv->status))
+ /* Re-enable all interrupts */
+ iwl_enable_interrupts(priv);
#ifdef CONFIG_IWLWIFI_DEBUG
if (iwl_debug_level & (IWL_DL_ISR)) {
@@ -4876,8 +4895,10 @@ unplugged:
return IRQ_HANDLED;
none:
- /* re-enable interrupts here since we don't have anything to service. */
- iwl_enable_interrupts(priv);
+ if (test_bit(STATUS_INT_ENABLED, &priv->status))
+ /* re-enable interrupts here since we don't have anything
+ * to service. */
+ iwl_enable_interrupts(priv);
spin_unlock(&priv->lock);
return IRQ_NONE;
}
---
Thanks,
Joonwoo
-
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