net: ipa: directly disable ipa-setup-ready interrupt

We currently maintain a "disabled" Boolean flag to determine whether
the "ipa-setup-ready" SMP2P IRQ handler does anything.  That flag
must be accessed under protection of a mutex.

Instead, disable the SMP2P interrupt when requested, which prevents
the interrupt handler from ever being called.  More importantly, it
synchronizes a thread disabling the interrupt with the completion of
the interrupt handler in case they run concurrently.

Use the IPA setup_complete flag rather than the disabled flag in the
handler to determine whether to ignore any interrupts arriving after
the first.

Rename the "disabled" flag to be "setup_disabled", to be specific
about its purpose.

Fixes: b5839de2348d ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
index df7639c39d7160a2c1de809c199e6fb23b3748e1..24bc112a072c6084075ae0925c0c66981ce08640 100644 (file)
--- a/drivers/net/ipa/ipa_smp2p.c
+++ b/drivers/net/ipa/ipa_smp2p.c
@@ -53,7 +53,7 @@
  * @setup_ready_irq:   IPA interrupt triggered by modem to signal GSI ready
  * @power_on:          Whether IPA power is on
  * @notified:          Whether modem has been notified of power state
- * @disabled:          Whether setup ready interrupt handling is disabled
+ * @setup_disabled:    Whether setup ready interrupt handler is disabled
  * @mutex:             Mutex protecting ready-interrupt/shutdown interlock
  * @panic_notifier:    Panic notifier structure
 */
@@ -67,7 +67,7 @@ struct ipa_smp2p {
        u32 setup_ready_irq;
        bool power_on;
        bool notified;
-       bool disabled;
+       bool setup_disabled;
        struct mutex mutex;
        struct notifier_block panic_notifier;
 };
@@ -155,11 +155,9 @@ static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id)
        struct device *dev;
        int ret;
 
-       mutex_lock(&smp2p->mutex);
-
-       if (smp2p->disabled)
-               goto out_mutex_unlock;
-       smp2p->disabled = true;         /* If any others arrive, ignore them */
+       /* Ignore any (spurious) interrupts received after the first */
+       if (smp2p->ipa->setup_complete)
+               return IRQ_HANDLED;
 
        /* Power needs to be active for setup */
        dev = &smp2p->ipa->pdev->dev;
@@ -176,8 +174,6 @@ static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id)
 out_power_put:
        pm_runtime_mark_last_busy(dev);
        (void)pm_runtime_put_autosuspend(dev);
-out_mutex_unlock:
-       mutex_unlock(&smp2p->mutex);
 
        return IRQ_HANDLED;
 }
@@ -322,7 +318,10 @@ void ipa_smp2p_disable(struct ipa *ipa)
 
        mutex_lock(&smp2p->mutex);
 
-       smp2p->disabled = true;
+       if (!smp2p->setup_disabled) {
+               disable_irq(smp2p->setup_ready_irq);
+               smp2p->setup_disabled = true;
+       }
 
        mutex_unlock(&smp2p->mutex);
 }