cnss_pci: fix the race condition bug in WLAN firmware table config

Update the synchronization process of the cnss platform driver
memory expansion and WLAN firmware table configuration from
the userspace through sysfs firmware update node.

CRs-Fixed: 2071560
Change-Id: I672ba84ad10c905be7855c1b8a930ac7adf349f1
Signed-off-by: Sarada Prasanna Garnayak <sgarna@codeaurora.org>

1 files changed, 14 insertions, 37 deletions

diff --git a/drivers/net/wireless/cnss/cnss_pci.c b/drivers/net/wireless/cnss/cnss_pci.c
index 22c59d8c3c45..c9412ca6e794 100644
--- a/drivers/net/wireless/cnss/cnss_pci.c
+++ b/drivers/net/wireless/cnss/cnss_pci.c
@@ -134,7 +134,6 @@ static DEFINE_SPINLOCK(pci_link_down_lock);
 #define FW_IMAGE_MISSION	(0x02)
 #define FW_IMAGE_BDATA		(0x03)
 #define FW_IMAGE_PRINT		(0x04)
-#define FW_SETUP_DELAY		2000
 
 #define SEG_METADATA		(0x01)
 #define SEG_NON_PAGED		(0x02)
@@ -274,10 +273,8 @@ static struct cnss_data {
 	u32 fw_dma_size;
 	u32 fw_seg_count;
 	struct segment_memory fw_seg_mem[MAX_NUM_OF_SEGMENTS];
-	atomic_t fw_store_in_progress;
 	/* Firmware setup complete lock */
 	struct mutex fw_setup_stat_lock;
-	struct completion fw_setup_complete;
 	void *bdata_cpu;
 	dma_addr_t bdata_dma;
 	u32 bdata_dma_size;
@@ -1374,15 +1371,6 @@ int cnss_get_fw_image(struct image_desc_info *image_desc_info)
 	    !penv->fw_seg_count || !penv->bdata_seg_count)
 		return -EINVAL;
 
-	/* Check for firmware setup trigger by usersapce is in progress
-	 * and wait for complition of firmware setup.
-	 */
-
-	if (atomic_read(&penv->fw_store_in_progress)) {
-		wait_for_completion_timeout(&penv->fw_setup_complete,
-					    msecs_to_jiffies(FW_SETUP_DELAY));
-	}
-
 	mutex_lock(&penv->fw_setup_stat_lock);
 	image_desc_info->fw_addr = penv->fw_dma;
 	image_desc_info->fw_size = penv->fw_dma_size;
@@ -1627,7 +1615,9 @@ static int cnss_wlan_pci_probe(struct pci_dev *pdev,
 		goto err_pcie_suspend;
 	}
 
+	mutex_lock(&penv->fw_setup_stat_lock);
 	cnss_wlan_fw_mem_alloc(pdev);
+	mutex_unlock(&penv->fw_setup_stat_lock);
 
 	ret = device_create_file(&penv->pldev->dev, &dev_attr_wlan_setup);
 
@@ -1874,17 +1864,11 @@ static ssize_t fw_image_setup_store(struct device *dev,
 	if (!penv)
 		return -ENODEV;
 
-	if (atomic_read(&penv->fw_store_in_progress)) {
-		pr_info("%s: Firmware setup in progress\n", __func__);
-		return 0;
-	}
-
-	atomic_set(&penv->fw_store_in_progress, 1);
-	init_completion(&penv->fw_setup_complete);
+	mutex_lock(&penv->fw_setup_stat_lock);
+	pr_info("%s: Firmware setup in progress\n", __func__);
 
 	if (kstrtoint(buf, 0, &val)) {
-		atomic_set(&penv->fw_store_in_progress, 0);
-		complete(&penv->fw_setup_complete);
+		mutex_unlock(&penv->fw_setup_stat_lock);
 		return -EINVAL;
 	}
 
@@ -1895,8 +1879,7 @@ static ssize_t fw_image_setup_store(struct device *dev,
 		if (ret != 0) {
 			pr_err("%s: Invalid parsing of FW image files %d",
 			       __func__, ret);
-			atomic_set(&penv->fw_store_in_progress, 0);
-			complete(&penv->fw_setup_complete);
+			mutex_unlock(&penv->fw_setup_stat_lock);
 			return -EINVAL;
 		}
 		penv->fw_image_setup = val;
@@ -1906,9 +1889,8 @@ static ssize_t fw_image_setup_store(struct device *dev,
 		penv->bmi_test = val;
 	}
 
-	atomic_set(&penv->fw_store_in_progress, 0);
-	complete(&penv->fw_setup_complete);
-
+	pr_info("%s: Firmware setup completed\n", __func__);
+	mutex_unlock(&penv->fw_setup_stat_lock);
 	return count;
 }
 
@@ -2007,16 +1989,21 @@ int cnss_get_codeswap_struct(struct codeswap_codeseg_info *swap_seg)
 {
 	struct codeswap_codeseg_info *cnss_seg_info = penv->cnss_seg_info;
 
+	mutex_lock(&penv->fw_setup_stat_lock);
 	if (!cnss_seg_info) {
 		swap_seg = NULL;
+		mutex_unlock(&penv->fw_setup_stat_lock);
 		return -ENOENT;
 	}
+
 	if (!atomic_read(&penv->fw_available)) {
 		pr_debug("%s: fw is not available\n", __func__);
+		mutex_unlock(&penv->fw_setup_stat_lock);
 		return -ENOENT;
 	}
 
 	*swap_seg = *cnss_seg_info;
+	mutex_unlock(&penv->fw_setup_stat_lock);
 
 	return 0;
 }
@@ -2035,15 +2022,6 @@ static void cnss_wlan_memory_expansion(void)
 	u_int32_t total_length = 0;
 	struct pci_dev *pdev;
 
-	/* Check for firmware setup trigger by usersapce is in progress
-	 * and wait for complition of firmware setup.
-	 */
-
-	if (atomic_read(&penv->fw_store_in_progress)) {
-		wait_for_completion_timeout(&penv->fw_setup_complete,
-					    msecs_to_jiffies(FW_SETUP_DELAY));
-	}
-
 	mutex_lock(&penv->fw_setup_stat_lock);
 	filename = cnss_wlan_get_evicted_data_file();
 	pdev = penv->pdev;
@@ -2859,6 +2837,7 @@ static int cnss_probe(struct platform_device *pdev)
 	penv->vreg_info.wlan_reg = NULL;
 	penv->vreg_info.state = VREG_OFF;
 	penv->pci_register_again = false;
+	mutex_init(&penv->fw_setup_stat_lock);
 
 	ret = cnss_wlan_get_resources(pdev);
 	if (ret)
@@ -3016,8 +2995,6 @@ skip_ramdump:
 	memset(phys_to_virt(0), 0, SZ_4K);
 #endif
 
-	atomic_set(&penv->fw_store_in_progress, 0);
-	mutex_init(&penv->fw_setup_stat_lock);
 	ret = device_create_file(dev, &dev_attr_fw_image_setup);
 	if (ret) {
 		pr_err("cnss: fw_image_setup sys file creation failed\n");