media: iris: Track flush responses to prevent premature completion

media: iris: Track flush responses to prevent premature completion

Currently, two types of flush commands are queued to the firmware,
the first flush queued as part of sequence change, does not wait for a
response, while the second flush queued as part of stop, expects a
completion response before proceeding further.

Due to timing issue, the flush response corresponding to the first
command could arrive after the second flush is issued. This casuses the
driver to incorrectly assume that the second flush has completed,
leading to the premature signaling of flush_completion.

To address this, introduce a counter to track the number of pending
flush responses and signal flush completion only when all expected
responses are received.

Cc: stable@vger.kernel.org
Fixes: 11712ce70f8e ("media: iris: implement vb2 streaming ops")
Reviewed-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Tested-by: Vikash Garodia <quic_vgarodia@quicinc.com> # on sa8775p-ride
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>