linux-kernel - [PATCH net-next 1/4] net: ipa: make IPA interrupt handler threaded only

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Date:   Tue, 27 Jul 2021 14:46:26 -0500
From:   Alex Elder <elder@...aro.org>
To:     davem@...emloft.net, kuba@...nel.org
Cc:     bjorn.andersson@...aro.org, evgreen@...omium.org,
        cpratapa@...eaurora.org, subashab@...eaurora.org, elder@...nel.org,
        netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH net-next 1/4] net: ipa: make IPA interrupt handler threaded only

When the IPA interrupt handler runs, the IPA core clock must already
be operational, and the interconnect providing access by the AP to
IPA config space must be enabled too.

Currently we ensure this by taking a top-level "stay awake" IPA
clock reference, but that will soon go away.  In preparation for
that, move all handling for the IPA IRQ into the thread function.

Signed-off-by: Alex Elder <elder@...aro.org>
---
 drivers/net/ipa/ipa_interrupt.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
index 9fd158dd90473..7dee4ebaf5a95 100644
--- a/drivers/net/ipa/ipa_interrupt.c
+++ b/drivers/net/ipa/ipa_interrupt.c
@@ -100,32 +100,22 @@ static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt)
 	}
 }
 
-/* Threaded part of the IPA IRQ handler */
+/* IPA IRQ handler is threaded */
 static irqreturn_t ipa_isr_thread(int irq, void *dev_id)
-{
-	struct ipa_interrupt *interrupt = dev_id;
-
-	ipa_clock_get(interrupt->ipa);
-
-	ipa_interrupt_process_all(interrupt);
-
-	ipa_clock_put(interrupt->ipa);
-
-	return IRQ_HANDLED;
-}
-
-/* Hard part (i.e., "real" IRQ handler) of the IRQ handler */
-static irqreturn_t ipa_isr(int irq, void *dev_id)
 {
 	struct ipa_interrupt *interrupt = dev_id;
 	struct ipa *ipa = interrupt->ipa;
 	u32 offset;
 	u32 mask;
 
+	ipa_clock_get(ipa);
+
 	offset = ipa_reg_irq_stts_offset(ipa->version);
 	mask = ioread32(ipa->reg_virt + offset);
-	if (mask & interrupt->enabled)
-		return IRQ_WAKE_THREAD;
+	if (mask & interrupt->enabled) {
+		ipa_interrupt_process_all(interrupt);
+		goto out_clock_put;
+	}
 
 	/* Nothing in the mask was supposed to cause an interrupt */
 	offset = ipa_reg_irq_clr_offset(ipa->version);
@@ -134,6 +124,9 @@ static irqreturn_t ipa_isr(int irq, void *dev_id)
 	dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n",
 		__func__, mask);
 
+out_clock_put:
+	ipa_clock_put(ipa);
+
 	return IRQ_HANDLED;
 }
 
@@ -260,7 +253,7 @@ struct ipa_interrupt *ipa_interrupt_config(struct ipa *ipa)
 	offset = ipa_reg_irq_en_offset(ipa->version);
 	iowrite32(0, ipa->reg_virt + offset);
 
-	ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT,
+	ret = request_threaded_irq(irq, NULL, ipa_isr_thread, IRQF_ONESHOT,
 				   "ipa", interrupt);
 	if (ret) {
 		dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
-- 
2.27.0