Commit 3f050110 authored by Eugen Hristev's avatar Eugen Hristev Committed by Mauro Carvalho Chehab
Browse files

media: atmel: atmel-isc-base: clamp wb gain coefficients 



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: default avatarEugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@kernel.org>
parent 76c97b0b

drivers/media/platform/atmel/atmel-isc-base.c

+4 −0
Original line number Diff line number Diff line
@@ -1375,6 +1375,10 @@ 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]);