linux-kernel - [PATCH 24/24] Input: xilinx_ps2 - use guard notation when acquiring spinlock

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Message-ID: <20240905041732.2034348-25-dmitry.torokhov@gmail.com>
Date: Wed,  4 Sep 2024 21:17:29 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: linux-input@...r.kernel.org
Cc: Pali Rohár <pali@...nel.org>,
	Helge Deller <deller@....de>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Wei Liu <wei.liu@...nel.org>,
	Dexuan Cui <decui@...rosoft.com>,
	Samuel Holland <samuel@...lland.org>,
	Lyude Paul <thatslyude@...il.com>,
	Michal Simek <michal.simek@....com>,
	Hans de Goede <hdegoede@...hat.com>,
	linux-kernel@...r.kernel.org,
	linux-hyperv@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-sunxi@...ts.linux.dev
Subject: [PATCH 24/24] Input: xilinx_ps2 - use guard notation when acquiring spinlock

Using guard notation makes the code more compact and error handling
more robust by ensuring that locks are released in all code paths
when control leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/input/serio/xilinx_ps2.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/input/serio/xilinx_ps2.c b/drivers/input/serio/xilinx_ps2.c
index 1543267d02ac..0316760168e5 100644
--- a/drivers/input/serio/xilinx_ps2.c
+++ b/drivers/input/serio/xilinx_ps2.c
@@ -155,22 +155,17 @@ static irqreturn_t xps2_interrupt(int irq, void *dev_id)
 static int sxps2_write(struct serio *pserio, unsigned char c)
 {
 	struct xps2data *drvdata = pserio->port_data;
-	unsigned long flags;
 	u32 sr;
-	int status = -1;
 
-	spin_lock_irqsave(&drvdata->lock, flags);
+	guard(spinlock_irqsave)(&drvdata->lock);
 
 	/* If the PS/2 transmitter is empty send a byte of data */
 	sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
-	if (!(sr & XPS2_STATUS_TX_FULL)) {
-		out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
-		status = 0;
-	}
+	if (sr & XPS2_STATUS_TX_FULL)
+		return -EAGAIN;
 
-	spin_unlock_irqrestore(&drvdata->lock, flags);
-
-	return status;
+	out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
+	return 0;
 }
 
 /**
-- 
2.46.0.469.g59c65b2a67-goog