Wrong place for rxbaddr/txbaddr to be in struct ath12k_spt_info

[Nicolas Escande]

Hi there,

Looking into a problem we have on an ath12k platform at work with a colleague,
I stumbled upon something that seems weird.

The interresting parts of dh.h:

struct ath12k_spt_info {
	dma_addr_t paddr;
	u64 *vaddr;
	struct ath12k_rx_desc_info *rxbaddr[ATH12K_NUM_RX_SPT_PAGES];
	struct ath12k_tx_desc_info *txbaddr[ATH12K_NUM_TX_SPT_PAGES];
};

...

struct ath12k_dp {
	struct ath12k_base *ab;
	...
	struct ath12k_spt_info *spt_info;
	u32 num_spt_pages;
	u32 rx_ppt_base;
	...
};

In dp.c we have ath12k_dp_cc_desc_init that allocs arrays of ath12k_rx_desc_info
stores the addresses of the individual desc in each of the spt entries using
ath12k_dp_cc_get_desc_addr_ptr(), but we also save the address of the whole
array for later cleanup by dp->spt_info->rxbaddr[i] = &rx_descs[0];

Surely this is wrong, with the current code we always use the first element of
dp->spt_info to store all the descriptors arrays. And the same goes for txbaddr.
I mean it works, but we loose memory for no purpose & make this part of the
driver harder to understand.

It should be something like:

diff --git a/drivers/net/wireless/ath/ath12k/dp.c b/drivers/net/wireless/ath/ath12k/dp.c
index 61aa78d8bd8c..ecd3b5c76d26 100644
--- a/drivers/net/wireless/ath/ath12k/dp.c
+++ b/drivers/net/wireless/ath/ath12k/dp.c
@@ -1162,7 +1162,7 @@ static void ath12k_dp_cc_cleanup(struct ath12k_base *ab)
 	spin_lock_bh(&dp->rx_desc_lock);
 
 	for (i = 0; i < ATH12K_NUM_RX_SPT_PAGES; i++) {
-		desc_info = dp->spt_info->rxbaddr[i];
+		desc_info = dp->rxbaddr[i];
 
 		for (j = 0; j < ATH12K_MAX_SPT_ENTRIES; j++) {
 			if (!desc_info[j].in_use) {
@@ -1181,11 +1181,11 @@ static void ath12k_dp_cc_cleanup(struct ath12k_base *ab)
 	}
 
 	for (i = 0; i < ATH12K_NUM_RX_SPT_PAGES; i++) {
-		if (!dp->spt_info->rxbaddr[i])
+		if (!dp->rxbaddr[i])
 			continue;
 
-		kfree(dp->spt_info->rxbaddr[i]);
-		dp->spt_info->rxbaddr[i] = NULL;
+		kfree(dp->rxbaddr[i]);
+		dp->rxbaddr[i] = NULL;
 	}
 
 	spin_unlock_bh(&dp->rx_desc_lock);
@@ -1220,11 +1220,11 @@ static void ath12k_dp_cc_cleanup(struct ath12k_base *ab)
 
 		for (i = 0; i < ATH12K_TX_SPT_PAGES_PER_POOL; i++) {
 			tx_spt_page = i + pool_id * ATH12K_TX_SPT_PAGES_PER_POOL;
-			if (!dp->spt_info->txbaddr[tx_spt_page])
+			if (!dp->txbaddr[tx_spt_page])
 				continue;
 
-			kfree(dp->spt_info->txbaddr[tx_spt_page]);
-			dp->spt_info->txbaddr[tx_spt_page] = NULL;
+			kfree(dp->txbaddr[tx_spt_page]);
+			dp->txbaddr[tx_spt_page] = NULL;
 		}
 
 		spin_unlock_bh(&dp->tx_desc_lock[pool_id]);
@@ -1415,7 +1415,7 @@ static int ath12k_dp_cc_desc_init(struct ath12k_base *ab)
 
 		ppt_idx = ATH12K_RX_SPT_PAGE_OFFSET + i;
 		cookie_ppt_idx = dp->rx_ppt_base + ppt_idx;
-		dp->spt_info->rxbaddr[i] = &rx_descs[0];
+		dp->rxbaddr[i] = &rx_descs[0];
 
 		for (j = 0; j < ATH12K_MAX_SPT_ENTRIES; j++) {
 			rx_descs[j].cookie = ath12k_dp_cc_cookie_gen(cookie_ppt_idx, j);
@@ -1445,7 +1445,7 @@ static int ath12k_dp_cc_desc_init(struct ath12k_base *ab)
 			tx_spt_page = i + pool_id * ATH12K_TX_SPT_PAGES_PER_POOL;
 			ppt_idx = ATH12K_TX_SPT_PAGE_OFFSET + tx_spt_page;
 
-			dp->spt_info->txbaddr[tx_spt_page] = &tx_descs[0];
+			dp->txbaddr[tx_spt_page] = &tx_descs[0];
 
 			for (j = 0; j < ATH12K_MAX_SPT_ENTRIES; j++) {
 				tx_descs[j].desc_id = ath12k_dp_cc_cookie_gen(ppt_idx, j);
diff --git a/drivers/net/wireless/ath/ath12k/dp.h b/drivers/net/wireless/ath/ath12k/dp.h
index b77497c14ac4..28c8bf22810c 100644
--- a/drivers/net/wireless/ath/ath12k/dp.h
+++ b/drivers/net/wireless/ath/ath12k/dp.h
@@ -300,8 +300,6 @@ struct ath12k_tx_desc_info {
 struct ath12k_spt_info {
 	dma_addr_t paddr;
 	u64 *vaddr;
-	struct ath12k_rx_desc_info *rxbaddr[ATH12K_NUM_RX_SPT_PAGES];
-	struct ath12k_tx_desc_info *txbaddr[ATH12K_NUM_TX_SPT_PAGES];
 };
 
 struct ath12k_reo_queue_ref {
@@ -352,6 +350,8 @@ struct ath12k_dp {
 	struct ath12k_spt_info *spt_info;
 	u32 num_spt_pages;
 	u32 rx_ppt_base;
+	struct ath12k_rx_desc_info *rxbaddr[ATH12K_NUM_RX_SPT_PAGES];
+	struct ath12k_tx_desc_info *txbaddr[ATH12K_NUM_TX_SPT_PAGES];
 	struct list_head rx_desc_free_list;
 	/* protects the free desc list */
 	spinlock_t rx_desc_lock;

Right ?