linux-kernel - [PATCH] usb: hub: Use max() to improve usb_set_lpm

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Message-ID: <20250917101235.58381-2-thorsten.blum@linux.dev>
Date: Wed, 17 Sep 2025 12:12:31 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Mathias Nyman <mathias.nyman@...ux.intel.com>,
	Alan Stern <stern@...land.harvard.edu>,
	Stefan Eichenberger <stefan.eichenberger@...adex.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
	Pawel Laszczak <pawell@...ence.com>,
	Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>,
	Ma Ke <make_ruc2021@....com>,
	linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] usb: hub: Use max() to improve usb_set_lpm_pel()

Use max() to simplify and improve the readability of usb_set_lpm_pel().

Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
---
 drivers/usb/core/hub.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 256fe8c86828..c8a543af3ad9 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -28,6 +28,7 @@
 #include <linux/usb/otg.h>
 #include <linux/usb/quirks.h>
 #include <linux/workqueue.h>
+#include <linux/minmax.h>
 #include <linux/mutex.h>
 #include <linux/random.h>
 #include <linux/pm_qos.h>
@@ -277,10 +278,7 @@ static void usb_set_lpm_pel(struct usb_device *udev,
 	 * device and the parent hub into U0.  The exit latency is the bigger of
 	 * the device exit latency or the hub exit latency.
 	 */
-	if (udev_exit_latency > hub_exit_latency)
-		first_link_pel = udev_exit_latency * 1000;
-	else
-		first_link_pel = hub_exit_latency * 1000;
+	first_link_pel = max(udev_exit_latency, hub_exit_latency) * 1000;
 
 	/*
 	 * When the hub starts to receive the LFPS, there is a slight delay for
@@ -294,10 +292,7 @@ static void usb_set_lpm_pel(struct usb_device *udev,
 	 * According to figure C-7 in the USB 3.0 spec, the PEL for this device
 	 * is the greater of the two exit latencies.
 	 */
-	if (first_link_pel > hub_pel)
-		udev_lpm_params->pel = first_link_pel;
-	else
-		udev_lpm_params->pel = hub_pel;
+	udev_lpm_params->pel = max(first_link_pel, hub_pel);
 }
 
 /*
-- 
2.50.1