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From:   =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date:   Thu, 12 Oct 2023 12:23:38 +0200
Subject: [PATCH 1/4] HID: core: remove #ifdef CONFIG_PM from hid_driver
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Message-Id: <20231012-hid-pm_ptr-v1-1-0a71531ca93b@weissschuh.net>
References: <20231012-hid-pm_ptr-v1-0-0a71531ca93b@weissschuh.net>
In-Reply-To: <20231012-hid-pm_ptr-v1-0-0a71531ca93b@weissschuh.net>
To:     Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org,
        =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Precedence: bulk

Allow HID drivers to pass ->suspend, ->resume and ->reset_resume via
pm_ptr().
Through the usage of pm_ptr() the CONFIG_PM-dependent code will always be
compiled, protecting against bitrot.
The linker will then garbage-collect the unused function avoiding any overhead.

The only overhead in the final kernel image and at runtime are a few
extra bytes in 'struct hid_driver'.

The same approach is chosen by 'struct usb_driver' and other subsystems.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 include/linux/hid.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/hid.h b/include/linux/hid.h
index 964ca1f15e3f..5a8387a4a712 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -833,11 +833,11 @@ struct hid_driver {
 	void (*feature_mapping)(struct hid_device *hdev,
 			struct hid_field *field,
 			struct hid_usage *usage);
-#ifdef CONFIG_PM
+
 	int (*suspend)(struct hid_device *hdev, pm_message_t message);
 	int (*resume)(struct hid_device *hdev);
 	int (*reset_resume)(struct hid_device *hdev);
-#endif
+
 /* private: */
 	struct device_driver driver;
 };

-- 
2.42.0