[libcamera-devel] [PATCH v2 2/2] utils: ipc: proxy: Reset ControlSerializer during IPA configure

[Kieran Bingham]

Hi Umang,

On 08/07/2021 11:54, Umang Jain wrote:
> ControlSerializer should be reset during IPA (re)configuration,
> so that it doesn't look up stale deserialized cache built from
> consecutive previous runs. This is already recommended in
> ControlSerializer docs but the implementation seems missing.
> 
> The stale cache lookup seems to the core issue with Bug #58.

Yikes. I guess this is also partially related to
https://bugs.libcamera.org/show_bug.cgi?id=31, but that is showing a
slightly different symptom of the effects of having to synchronise
control lists across the IPC.

> Bug: https://bugs.libcamera.org/show_bug.cgi?id=58
> Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> Reviewed-by: Paul Elder <paul.elder at ideasonboard.com>

Tested locally, and fixes things as far as I can tell.

Indeed there are further issues that appear after this related to an fd
leak, but they are separate and I do not believe caused by this patch
(but only visible when the system can run long enough thanks to this fix).

Tested-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

> ---
>  .../generators/libcamera_templates/module_ipa_proxy.cpp.tmpl   | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/utils/ipc/generators/libcamera_templates/module_ipa_proxy.cpp.tmpl b/utils/ipc/generators/libcamera_templates/module_ipa_proxy.cpp.tmpl
> index 5a64fe9c..a4e008c7 100644
> --- a/utils/ipc/generators/libcamera_templates/module_ipa_proxy.cpp.tmpl
> +++ b/utils/ipc/generators/libcamera_templates/module_ipa_proxy.cpp.tmpl
> @@ -184,6 +184,9 @@ void {{proxy_name}}::recvMessage(const IPCMessage &data)
>  
>  {{proxy_funcs.func_sig(proxy_name, method, "IPC")}}
>  {
> +{%- if method.mojom_name == "configure" %}
> +	controlSerializer_.reset();
> +{%- endif %}
>  {%- set has_output = true if method|method_param_outputs|length > 0 or method|method_return_value != "void" %}
>  {%- set cmd = cmd_enum_name + "::" + method.mojom_name|cap %}
>  	IPCMessage::Header _header = { static_cast<uint32_t>({{cmd}}), seq_++ };
>