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From: Arnd Bergmann <arnd@kernel.org>
To: Minghsiu Tsai <minghsiu.tsai@mediatek.com>,
	Houlong Wei <houlong.wei@mediatek.com>,
	Andrew-CT Chen <andrew-ct.chen@mediatek.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	Tiffany Lin <tiffany.lin@mediatek.com>,
	Yunfei Dong <yunfei.dong@mediatek.com>,
	Hans Verkuil <hverkuil-cisco@xs4all.nl>,
	Nicolas Dufresne <nicolas.dufresne@collabora.com>,
	Alexandre Courbot <acourbot@chromium.org>,
	Pi-Hsun Shih <pihsun@chromium.org>,
	linux-media@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org
Subject: [PATCH] media: mediatek: vcodec: avoid -Wcast-function-type-strict warning
Date: Sat, 24 Feb 2024 13:10:22 +0100
Message-Id: <20240224121059.1806691-1-arnd@kernel.org>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: Arnd Bergmann <arnd@arndb.de>

The ipi handler here tries hard to maintain const-ness of its argument,
but by doing that causes a warning about function type casts:

drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c:38:32: error: cast from 'mtk_vcodec_ipi_handler' (aka 'void (*)(void *, unsigned int, void *)') to 'ipi_handler_t' (aka 'void (*)(const void *, unsigned int, void *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
   38 |         ipi_handler_t handler_const = (ipi_handler_t)handler;
      |                                       ^~~~~~~~~~~~~~~~~~~~~~

Remove the hack and just use a non-const argument.

Fixes: bf1d556ad4e0 ("media: mtk-vcodec: abstract firmware interface")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/media/platform/mediatek/mdp/mtk_mdp_vpu.c      |  2 +-
 .../mediatek/vcodec/common/mtk_vcodec_fw_vpu.c         | 10 +---------
 drivers/media/platform/mediatek/vpu/mtk_vpu.c          |  2 +-
 drivers/media/platform/mediatek/vpu/mtk_vpu.h          |  2 +-
 4 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/mediatek/mdp/mtk_mdp_vpu.c b/drivers/media/platform/mediatek/mdp/mtk_mdp_vpu.c
index b065ccd06914..378a1cba0144 100644
--- a/drivers/media/platform/mediatek/mdp/mtk_mdp_vpu.c
+++ b/drivers/media/platform/mediatek/mdp/mtk_mdp_vpu.c
@@ -26,7 +26,7 @@ static void mtk_mdp_vpu_handle_init_ack(const struct mdp_ipi_comm_ack *msg)
 	vpu->inst_addr = msg->vpu_inst_addr;
 }
 
-static void mtk_mdp_vpu_ipi_handler(const void *data, unsigned int len,
+static void mtk_mdp_vpu_ipi_handler(void *data, unsigned int len,
 				    void *priv)
 {
 	const struct mdp_ipi_comm_ack *msg = data;
diff --git a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
index 9f6e4b59455d..4c34344dc7dc 100644
--- a/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
+++ b/drivers/media/platform/mediatek/vcodec/common/mtk_vcodec_fw_vpu.c
@@ -29,15 +29,7 @@ static int mtk_vcodec_vpu_set_ipi_register(struct mtk_vcodec_fw *fw, int id,
 					   mtk_vcodec_ipi_handler handler,
 					   const char *name, void *priv)
 {
-	/*
-	 * The handler we receive takes a void * as its first argument. We
-	 * cannot change this because it needs to be passed down to the rproc
-	 * subsystem when SCP is used. VPU takes a const argument, which is
-	 * more constrained, so the conversion below is safe.
-	 */
-	ipi_handler_t handler_const = (ipi_handler_t)handler;
-
-	return vpu_ipi_register(fw->pdev, id, handler_const, name, priv);
+	return vpu_ipi_register(fw->pdev, id, handler, name, priv);
 }
 
 static int mtk_vcodec_vpu_ipi_send(struct mtk_vcodec_fw *fw, int id, void *buf,
diff --git a/drivers/media/platform/mediatek/vpu/mtk_vpu.c b/drivers/media/platform/mediatek/vpu/mtk_vpu.c
index 7243604a82a5..724ae7c2ab3b 100644
--- a/drivers/media/platform/mediatek/vpu/mtk_vpu.c
+++ b/drivers/media/platform/mediatek/vpu/mtk_vpu.c
@@ -635,7 +635,7 @@ int vpu_load_firmware(struct platform_device *pdev)
 }
 EXPORT_SYMBOL_GPL(vpu_load_firmware);
 
-static void vpu_init_ipi_handler(const void *data, unsigned int len, void *priv)
+static void vpu_init_ipi_handler(void *data, unsigned int len, void *priv)
 {
 	struct mtk_vpu *vpu = priv;
 	const struct vpu_run *run = data;
diff --git a/drivers/media/platform/mediatek/vpu/mtk_vpu.h b/drivers/media/platform/mediatek/vpu/mtk_vpu.h
index a56053ff135a..da05f3e74081 100644
--- a/drivers/media/platform/mediatek/vpu/mtk_vpu.h
+++ b/drivers/media/platform/mediatek/vpu/mtk_vpu.h
@@ -17,7 +17,7 @@
  * VPU interfaces with other blocks by share memory and interrupt.
  */
 
-typedef void (*ipi_handler_t) (const void *data,
+typedef void (*ipi_handler_t) (void *data,
 			       unsigned int len,
 			       void *priv);
 
-- 
2.39.2