Commit dcb166ee authored by Dan Carpenter's avatar Dan Carpenter Committed by Chun-Kuang Hu
Browse files

drm/mediatek: dsi: fix error codes in mtk_dsi_host_transfer() 



There is a type bug because the return statement:

        return ret < 0 ? ret : recv_cnt;

The issue is that ret is an int, recv_cnt is a u32 and the function
returns ssize_t, which is a signed long.  The way that the type promotion
works is that the negative error codes are first cast to u32 and then
to signed long.  The error codes end up being positive instead of
negative and the callers treat them as success.

Fixes: 81cc7e51 ("drm/mediatek: Allow commands to be sent during video mode")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202412210801.iADw0oIH-lkp@intel.com/


Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: default avatarMattijs Korpershoek <mkorpershoek@baylibre.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/b754a408-4f39-4e37-b52d-7706c132e27f@stanley.mountain/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent cd5b6ba7

drivers/gpu/drm/mediatek/mtk_dsi.c

+3 −3
Original line number Diff line number Diff line
@@ -1116,12 +1116,12 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, 
				     const struct mipi_dsi_msg *msg)

{

	struct mtk_dsi *dsi = host_to_dsi(host);

	u32 recv_cnt, i;

	ssize_t recv_cnt;

	u8 read_data[16];

	void *src_addr;

	u8 irq_flag = CMD_DONE_INT_FLAG;

	u32 dsi_mode;

	int ret;

	int ret, i;



	dsi_mode = readl(dsi->regs + DSI_MODE_CTRL);

	if (dsi_mode & MODE) {
@@ -1170,7 +1170,7 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host, 
	if (recv_cnt)

		memcpy(msg->rx_buf, src_addr, recv_cnt);



	DRM_INFO("dsi get %d byte data from the panel address(0x%x)\n",

	DRM_INFO("dsi get %zd byte data from the panel address(0x%x)\n",

		 recv_cnt, *((u8 *)(msg->tx_buf)));



restore_dsi_mode: