[PATCH 21/21] media: atmel: atmel-isc-base: clamp wb gain coefficients
From: Eugen Hristev <hidden>
Date: 2021-10-22 07:55:30
Also in:
linux-devicetree, linux-media, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
White balance computed gains can overflow above the 13 bits hardware coefficient that can be used, in some specific scenarios like a subexposure from the sensor when the image is mostly black. In this case the computed gain has to be clamped to the maximum value allowed by the hardware. Signed-off-by: Eugen Hristev <redacted> --- drivers/media/platform/atmel/atmel-isc-base.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
index 071ac5eec7ec..53141de78f67 100644
--- a/drivers/media/platform/atmel/atmel-isc-base.c
+++ b/drivers/media/platform/atmel/atmel-isc-base.c@@ -1416,6 +1416,10 @@ static void isc_wb_update(struct isc_ctrls *ctrls) /* multiply both gains and adjust for decimals */ ctrls->gain[c] = s_gain[c] * gw_gain[c]; ctrls->gain[c] >>= 9; + + /* make sure we are not out of range */ + ctrls->gain[c] = clamp_val(ctrls->gain[c], 0, GENMASK(12, 0)); + v4l2_dbg(1, debug, &isc->v4l2_dev, "isc wb: component %d, final gain %u\n", c, ctrls->gain[c]);
--
2.25.1
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