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From:   Andrey Konovalov <andrey.konovalov@linaro.org>
To:     junak.pub@gmail.com, robert.foss@linaro.org,
        sakari.ailus@linux.intel.com
Cc:     todor.too@gmail.com, agross@kernel.org, bjorn.andersson@linaro.org,
        mchehab@kernel.org, laurent.pinchart@ideasonboard.com,
        jacopo@jmondi.org, linux-media@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andrey Konovalov <andrey.konovalov@linaro.org>
Subject: [PATCH v3 1/3] v4l: common: v4l2_get_link_freq: add printing a warning
Date:   Wed,  3 Mar 2021 20:42:48 +0300
Message-Id: <20210303174250.11405-2-andrey.konovalov@linaro.org>
In-Reply-To: <20210303174250.11405-1-andrey.konovalov@linaro.org>
References: <20210303174250.11405-1-andrey.konovalov@linaro.org>
Precedence: bulk

Print a warning if V4L2_CID_LINK_FREQ control is not implemented.

Signed-off-by: Andrey Konovalov <andrey.konovalov@linaro.org>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/v4l2-core/v4l2-common.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 133d20e40f82..04af03285a20 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -469,6 +469,11 @@ s64 v4l2_get_link_freq(struct v4l2_ctrl_handler *handler, unsigned int mul,
 			return -ENOENT;
 
 		freq = div_u64(v4l2_ctrl_g_ctrl_int64(ctrl) * mul, div);
+
+		pr_warn("%s: Link frequency estimated using pixel rate: result might be inaccurate\n",
+			__func__);
+		pr_warn("%s: Consider implementing support for V4L2_CID_LINK_FREQ in the transmitter driver\n",
+			__func__);
 	}
 
 	return freq > 0 ? freq : -EINVAL;
-- 
2.17.1