[PATCH] libcamera: software_isp: Reset stored exposure in black level

[Robert Mader]

Thanks!

Tested-by: Robert Mader <robert.mader at collabora.com>

On 17.03.25 12:26, Milan Zamazal wrote:
> Automatic black level setting in software ISP updates the determined
> black level value when exposure or gain change.  It stores the last
> exposure and gain values to detect the change.
>
> BlackLevel::configure() resets the stored black level value but not the
> exposure and gain values.  This can prevent updating the black value and
> cause bad image output e.g. after suspending and resuming a camera, if
> exposure and gain remain unchanged.
>
> Let's reset the stored exposure and gain values in
> BlackLevel::configure() to fix the problem.
>
> Bug: https://bugs.libcamera.org/show_bug.cgi?id=259
> Signed-off-by: Milan Zamazal <mzamazal at redhat.com>
> ---
>   src/ipa/simple/algorithms/blc.cpp | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/src/ipa/simple/algorithms/blc.cpp b/src/ipa/simple/algorithms/blc.cpp
> index 1d7d370b..14cf31bf 100644
> --- a/src/ipa/simple/algorithms/blc.cpp
> +++ b/src/ipa/simple/algorithms/blc.cpp
> @@ -1,6 +1,6 @@
>   /* SPDX-License-Identifier: LGPL-2.1-or-later */
>   /*
> - * Copyright (C) 2024, Red Hat Inc.
> + * Copyright (C) 2024-2025, Red Hat Inc.
>    *
>    * Black level handling
>    */
> @@ -38,6 +38,9 @@ int BlackLevel::init([[maybe_unused]] IPAContext &context,
>   int BlackLevel::configure(IPAContext &context,
>   			  [[maybe_unused]] const IPAConfigInfo &configInfo)
>   {
> +	exposure_ = 0;
> +	gain_ = 0;
> +
>   	if (definedLevel_.has_value())
>   		context.configuration.black.level = definedLevel_;
>   	context.activeState.blc.level =