ASoC: SOF: add flag to disable IMR restore to sof_debug

Add flag _IGNORE_D3_PERSISTENT to disable IMR restore feature to
the sof_debug module parameter.

The IMR restore feature will be enabled for all Intel cAVS platforms by
default, but setting the flag _IGNORE_D3_PERSISTENT can help to disable
the feature for debug purpose, to rule out any possible regression
introduced by the change of not re-downloading firmware to the DSP at
resuming from suspended state.
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Keyon Jie <yang.jie@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220120231532.196926-6-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/hda-loader.c

@@ -21,6 +21,7 @@
 #include <sound/sof.h>
 #include "ext_manifest.h"
 #include "../ops.h"
+#include "../sof-priv.h"
 #include "hda.h"
 
 #define HDA_CL_STREAM_FORMAT 0x40
@@ -396,6 +397,7 @@ int hda_dsp_cl_boot_firmware(struct snd_sof_dev *sdev)
 	int ret, ret1, i;
 
 	if ((sdev->fw_ready.flags & SOF_IPC_INFO_D3_PERSISTENT) &&
+	    !(sof_debug_check_flag(SOF_DBG_IGNORE_D3_PERSISTENT)) &&
 	    !sdev->first_boot) {
 		dev_dbg(sdev->dev, "IMR restore supported, booting from IMR directly\n");
 		return hda_dsp_boot_imr(sdev);

sound/soc/sof/sof-priv.h

@@ -34,6 +34,9 @@
 							* on primary core
 							*/
 #define SOF_DBG_PRINT_ALL_DUMPS		BIT(6) /* Print all ipc and dsp dumps */
+#define SOF_DBG_IGNORE_D3_PERSISTENT		BIT(7) /* ignore the DSP D3 persistent capability
+							* and always download firmware upon D3 exit
+							*/
 
 /* Flag definitions used for controlling the DSP dump behavior */
 #define SOF_DBG_DUMP_REGS		BIT(0)