media: amphion: fix a bug that vpu core may not resume after suspend

driver will enable the vpu core when request the first instance
on the core.
one vpu core can only support 8 streaming instances in the same
time, the instance won't be added to core's list before streamon.

so the actual instance count may be greater then the number in
the core's list.

in pm resume callback, driver will resume the core immediately if
core's list is not empty.
but this check is not accurate,
if suspend during one instance is requested, but not streamon,
then after suspend, the core won't be resume, and led to instance failure.

use the request_count instead of the core's list to check
whether is the core needed to resume immediately after suspend.

And it can make the pm suspend and resume callback more clear.

Fixes: 9f599f351e86 ("media: amphion: add vpu core driver")
Signed-off-by: Ming Qian <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/amphion/vpu.h

···
 enum vpu_core_state {
 	VPU_CORE_DEINIT = 0,
 	VPU_CORE_ACTIVE,
-	VPU_CORE_SNAPSHOT,
 	VPU_CORE_HANG
 };
 

drivers/media/platform/amphion/vpu_core.c

···
 		core->supported_instance_count = min(core->supported_instance_count, count);
 	}
 	core->fw_version = fw_version;
-	core->state = VPU_CORE_ACTIVE;
+	vpu_core_set_state(core, VPU_CORE_ACTIVE);
 
 	return 0;
 }
···
 	return __vpu_alloc_dma(core->dev, buf);
 }
 
-static void vpu_core_check_hang(struct vpu_core *core)
+void vpu_core_set_state(struct vpu_core *core, enum vpu_core_state state)
 {
-	if (core->hang_mask)
-		core->state = VPU_CORE_HANG;
+	if (state != core->state)
+		vpu_trace(core->dev, "vpu core state change from %d to %d\n", core->state, state);
+	core->state = state;
+	if (core->state == VPU_CORE_DEINIT)
+		core->hang_mask = 0;
+}
+
+static void vpu_core_update_state(struct vpu_core *core)
+{
+	if (!vpu_iface_get_power_state(core)) {
+		if (core->request_count)
+			vpu_core_set_state(core, VPU_CORE_HANG);
+		else
+			vpu_core_set_state(core, VPU_CORE_DEINIT);
+
+	} else if (core->state == VPU_CORE_ACTIVE && core->hang_mask) {
+		vpu_core_set_state(core, VPU_CORE_HANG);
+	}
 }
 
 static struct vpu_core *vpu_core_find_proper_by_type(struct vpu_dev *vpu, u32 type)
···
 		dev_dbg(c->dev, "instance_mask = 0x%lx, state = %d\n", c->instance_mask, c->state);
 		if (c->type != type)
 			continue;
+		mutex_lock(&c->lock);
+		vpu_core_update_state(c);
+		mutex_unlock(&c->lock);
 		if (c->state == VPU_CORE_DEINIT) {
 			core = c;
 			break;
 		}
-		vpu_core_check_hang(c);
 		if (c->state != VPU_CORE_ACTIVE)
 			continue;
 		if (c->request_count < request_count) {
···
 	}
 
 	mutex_lock(&core->lock);
+	if (core->state != VPU_CORE_ACTIVE) {
+		dev_err(core->dev, "vpu core is not active, state = %d\n", core->state);
+		ret = -EINVAL;
+		goto exit;
+	}
+
 	if (inst->id >= 0 && inst->id < core->supported_instance_count)
 		goto exit;
 
···
 		vpu_core_release_instance(core, inst->id);
 		inst->id = VPU_INST_NULL_ID;
 	}
-	vpu_core_check_hang(core);
+	vpu_core_update_state(core);
 	if (core->state == VPU_CORE_HANG && !core->instance_mask) {
 		int err;
 
···
 		err = vpu_core_sw_reset(core);
 		mutex_lock(&core->lock);
 		if (!err) {
-			core->state = VPU_CORE_ACTIVE;
+			vpu_core_set_state(core, VPU_CORE_ACTIVE);
 			core->hang_mask = 0;
 		}
 	}
···
 	mutex_init(&core->cmd_lock);
 	init_completion(&core->cmp);
 	init_waitqueue_head(&core->ack_wq);
-	core->state = VPU_CORE_DEINIT;
+	vpu_core_set_state(core, VPU_CORE_DEINIT);
 
 	core->res = of_device_get_match_data(dev);
 	if (!core->res)
···
 	mutex_lock(&core->lock);
 	pm_runtime_resume_and_get(dev);
 	vpu_core_get_vpu(core);
-	if (core->state != VPU_CORE_SNAPSHOT)
-		goto exit;
 
-	if (!vpu_iface_get_power_state(core)) {
-		if (!list_empty(&core->instances)) {
+	if (core->request_count) {
+		if (!vpu_iface_get_power_state(core))
 			ret = vpu_core_boot(core, false);
-			if (ret) {
-				dev_err(core->dev, "%s boot fail\n", __func__);
-				core->state = VPU_CORE_DEINIT;
-				goto exit;
-			}
-		} else {
-			core->state = VPU_CORE_DEINIT;
-		}
-	} else {
-		if (!list_empty(&core->instances)) {
+		else
 			ret = vpu_core_sw_reset(core);
-			if (ret) {
-				dev_err(core->dev, "%s sw_reset fail\n", __func__);
-				core->state = VPU_CORE_HANG;
-				goto exit;
-			}
+		if (ret) {
+			dev_err(core->dev, "resume fail\n");
+			vpu_core_set_state(core, VPU_CORE_HANG);
 		}
-		core->state = VPU_CORE_ACTIVE;
 	}
-
-exit:
+	vpu_core_update_state(core);
 	pm_runtime_put_sync(dev);
 	mutex_unlock(&core->lock);
 
···
 	int ret = 0;
 
 	mutex_lock(&core->lock);
-	if (core->state == VPU_CORE_ACTIVE) {
-		if (!list_empty(&core->instances)) {
-			ret = vpu_core_snapshot(core);
-			if (ret) {
-				mutex_unlock(&core->lock);
-				return ret;
-			}
-		}
-
-		core->state = VPU_CORE_SNAPSHOT;
-	}
+	if (core->request_count)
+		ret = vpu_core_snapshot(core);
 	mutex_unlock(&core->lock);
+	if (ret)
+		return ret;
 
 	vpu_core_cancel_work(core);
 

drivers/media/platform/amphion/vpu_core.h

···
 int vpu_alloc_dma(struct vpu_core *core, struct vpu_buffer *buf);
 void vpu_free_dma(struct vpu_buffer *buf);
 struct vpu_inst *vpu_core_find_instance(struct vpu_core *core, u32 index);
+void vpu_core_set_state(struct vpu_core *core, enum vpu_core_state state);
 
 #endif

drivers/media/platform/amphion/vpu_dbg.c

···
 #include <linux/debugfs.h>
 #include "vpu.h"
 #include "vpu_defs.h"
+#include "vpu_core.h"
 #include "vpu_helpers.h"
 #include "vpu_cmds.h"
 #include "vpu_rpc.h"
···
 	if (seq_write(s, str, num))
 		return 0;
 
+	num = scnprintf(str, sizeof(str), "power %s\n",
+			vpu_iface_get_power_state(core) ? "on" : "off");
+	if (seq_write(s, str, num))
+		return 0;
 	num = scnprintf(str, sizeof(str), "state = %d\n", core->state);
 	if (seq_write(s, str, num))
 		return 0;
···
 
 	pm_runtime_resume_and_get(core->dev);
 	mutex_lock(&core->lock);
-	if (core->state != VPU_CORE_DEINIT && !core->instance_mask) {
+	if (vpu_iface_get_power_state(core) && !core->request_count) {
 		dev_info(core->dev, "reset\n");
 		if (!vpu_core_sw_reset(core)) {
-			core->state = VPU_CORE_ACTIVE;
+			vpu_core_set_state(core, VPU_CORE_ACTIVE);
 			core->hang_mask = 0;
 		}
 	}