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From:   Alex Elder <elder@linaro.org>
To:     davem@davemloft.net, kuba@kernel.org
Cc:     bjorn.andersson@linaro.org, evgreen@chromium.org,
        cpratapa@codeaurora.org, subashab@codeaurora.org, elder@kernel.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net-next 3/5] net: ipa: don't use ipa_clock_get() in "ipa_uc.c"
Date:   Thu, 19 Aug 2021 17:19:25 -0500
Message-Id: <20210819221927.3286267-4-elder@linaro.org>
In-Reply-To: <20210819221927.3286267-1-elder@linaro.org>
References: <20210819221927.3286267-1-elder@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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Replace the ipa_clock_get() call in ipa_uc_clock() when taking the
"proxy" clock reference for the microcontroller with a call to
pm_runtime_get_sync().  Replace calls of ipa_clock_put() for the
microcontroller with pm_runtime_put() calls instead.

There is a chance we get an error when taking the microcontroller
power reference.  This is an unlikely scenario, where system suspend
is initiated just before we learn the modem is booting.  For now
we'll just accept that this could occur, and report it if it does.

Signed-off-by: Alex Elder <elder@linaro.org>
---
 drivers/net/ipa/ipa_uc.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ipa/ipa_uc.c b/drivers/net/ipa/ipa_uc.c
index 9c8818c390731..a0bdd25b65b4f 100644
--- a/drivers/net/ipa/ipa_uc.c
+++ b/drivers/net/ipa/ipa_uc.c
@@ -7,9 +7,9 @@
 #include <linux/types.h>
 #include <linux/io.h>
 #include <linux/delay.h>
+#include <linux/pm_runtime.h>
 
 #include "ipa.h"
-#include "ipa_clock.h"
 #include "ipa_uc.h"
 
 /**
@@ -154,7 +154,7 @@ static void ipa_uc_response_hdlr(struct ipa *ipa, enum ipa_irq_id irq_id)
 	case IPA_UC_RESPONSE_INIT_COMPLETED:
 		if (ipa->uc_clocked) {
 			ipa->uc_loaded = true;
-			(void)ipa_clock_put(ipa);
+			(void)pm_runtime_put(dev);
 			ipa->uc_clocked = false;
 		} else {
 			dev_warn(dev, "unexpected init_completed response\n");
@@ -182,25 +182,29 @@ void ipa_uc_deconfig(struct ipa *ipa)
 	ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_1);
 	ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_0);
 	if (ipa->uc_clocked)
-		(void)ipa_clock_put(ipa);
+		(void)pm_runtime_put(&ipa->pdev->dev);
 }
 
 /* Take a proxy clock reference for the microcontroller */
 void ipa_uc_clock(struct ipa *ipa)
 {
 	static bool already;
+	struct device *dev;
 	int ret;
 
 	if (already)
 		return;
 	already = true;		/* Only do this on first boot */
 
-	/* This clock reference dropped in ipa_uc_response_hdlr() above */
-	ret = ipa_clock_get(ipa);
-	if (WARN(ret < 0, "error %d getting proxy clock\n", ret))
-		(void)ipa_clock_put(ipa);
-
-	ipa->uc_clocked = ret >= 0;
+	/* This power reference dropped in ipa_uc_response_hdlr() above */
+	dev = &ipa->pdev->dev;
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		dev_err(dev, "error %d getting proxy power\n", ret);
+	} else {
+		ipa->uc_clocked = true;
+	}
 }
 
 /* Send a command to the microcontroller */
-- 
2.27.0