media: venus: fix multiple encoder crash

Currently we are considering the instances which are available
in core->inst list for load calculation in min_loaded_core()
function, but this is incorrect because by the time we call
decide_core() for second instance, the third instance not
filled yet codec_freq_data pointer.

Solve this by considering the instances whose session has started.

Cc: stable@vger.kernel.org # v5.7+
Fixes: 4ebf969375 ("media: venus: introduce core selection")
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mansur Alisha Shaik <mansur@codeaurora.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/qcom/venus/pm_helpers.c

@@ -496,6 +496,10 @@ min_loaded_core(struct venus_inst *inst, u32 *min_coreid, u32 *min_load)
 	list_for_each_entry(inst_pos, &core->instances, list) {
 		if (inst_pos == inst)
 			continue;
+
+		if (inst_pos->state != INST_START)
+			continue;
+
 		vpp_freq = inst_pos->clk_data.codec_freq_data->vpp_freq;
 		coreid = inst_pos->clk_data.core_id;