From 479ffdf8425de523a653fb7fad8fa207b495e254 Mon Sep 17 00:00:00 2001
From: Cao Jian <jian.cao@amlogic.com>
Date: Fri, 17 Jul 2020 14:18:22 +0800
Subject: [PATCH] gdc: add a probed flag to avoid crash [1/1]

PD#SWPL-29848

Problem:
on platforms which GDC are not supported
if create_gdc_work_queue is invoked
a crash occurs

Solution:
add a probed flag to avoid crash
add a interface is_gdc_supported to query

Verify:
g12b/tm2

Change-Id: I65b88294822d8a2c7429d375039fee962b9612aa
Signed-off-by: Cao Jian <jian.cao@amlogic.com>
---
 drivers/amlogic/media/gdc/app/gdc_module.c     |  2 ++
 drivers/amlogic/media/gdc/app/gdc_wq.c         | 13 +++++++++++++
 drivers/amlogic/media/gdc/inc/gdc/gdc_config.h |  1 +
 include/linux/amlogic/media/gdc/gdc.h          |  3 ++-
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/amlogic/media/gdc/app/gdc_module.c b/drivers/amlogic/media/gdc/app/gdc_module.c
index 1dd5eb9bf573..7933c576b739 100644
--- a/drivers/amlogic/media/gdc/app/gdc_module.c
+++ b/drivers/amlogic/media/gdc/app/gdc_module.c
@@ -1900,6 +1900,8 @@ static int gdc_platform_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, gdc_dev);
 	gdc_pwr_config(false);
 
+	gdc_manager.probed = 1;
+
 	return rc;
 }
 
diff --git a/drivers/amlogic/media/gdc/app/gdc_wq.c b/drivers/amlogic/media/gdc/app/gdc_wq.c
index f2fb62f7ee2b..29180925a851 100644
--- a/drivers/amlogic/media/gdc/app/gdc_wq.c
+++ b/drivers/amlogic/media/gdc/app/gdc_wq.c
@@ -324,6 +324,15 @@ static inline int work_queue_no_space(struct gdc_context_s *queue)
 	return  list_empty(&queue->free_queue);
 }
 
+bool is_gdc_supported(void)
+{
+	if (gdc_manager.probed)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(is_gdc_supported);
+
 struct gdc_context_s *create_gdc_work_queue(void)
 {
 	int  i;
@@ -331,6 +340,10 @@ struct gdc_context_s *create_gdc_work_queue(void)
 	struct gdc_context_s *gdc_work_queue;
 	int  empty;
 
+	if (!gdc_manager.probed) {
+		gdc_log(LOG_INFO, "GDC is not supported for this chip\n");
+		return NULL;
+	}
 	gdc_work_queue = kzalloc(sizeof(struct gdc_context_s), GFP_KERNEL);
 	if (IS_ERR(gdc_work_queue)) {
 		gdc_log(LOG_ERR, "can't create work queue\n");
diff --git a/drivers/amlogic/media/gdc/inc/gdc/gdc_config.h b/drivers/amlogic/media/gdc/inc/gdc/gdc_config.h
index 866b2756f7c1..5cc598b0e27b 100644
--- a/drivers/amlogic/media/gdc/inc/gdc/gdc_config.h
+++ b/drivers/amlogic/media/gdc/inc/gdc/gdc_config.h
@@ -56,6 +56,7 @@ struct gdc_manager_s {
 	int gdc_state;
 	int process_queue_state;//thread running flag
 	struct meson_gdc_dev_t *gdc_dev;
+	int probed;
 };
 
 extern struct gdc_manager_s gdc_manager;
diff --git a/include/linux/amlogic/media/gdc/gdc.h b/include/linux/amlogic/media/gdc/gdc.h
index 15c9faa9f07b..42c4b80c0c4b 100644
--- a/include/linux/amlogic/media/gdc/gdc.h
+++ b/include/linux/amlogic/media/gdc/gdc.h
@@ -165,9 +165,10 @@ struct gdc_phy_setting {
 	char config_name[CONFIG_PATH_LENG];
 };
 
+bool is_gdc_supported(void);
+struct gdc_context_s *create_gdc_work_queue(void);
 int gdc_process_phys(struct gdc_context_s *context,
 		     struct gdc_phy_setting *gs);
-struct gdc_context_s *create_gdc_work_queue(void);
 int destroy_gdc_work_queue(struct gdc_context_s *gdc_work_queue);
 
 #endif