qtnfmac: module param sanity check

Linux built-in circ_buf implementation assumes that that the
circular buffer length is a power of 2. Make sure that
rx and tx descriptor queue lengths are power-of-2.

Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/quantenna/qtnfmac/pearl/pcie.c b/drivers/net/wireless/quantenna/qtnfmac/pearl/pcie.c
index cd2f2b6..fd552d6 100644 (file)
--- a/drivers/net/wireless/quantenna/qtnfmac/pearl/pcie.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/pearl/pcie.c
@@ -26,6 +26,7 @@
 #include <linux/crc32.h>
 #include <linux/spinlock.h>
 #include <linux/circ_buf.h>
+#include <linux/log2.h>
 
 #include "qtn_hw_ids.h"
 #include "pcie_bus_priv.h"
@@ -39,11 +40,11 @@ MODULE_PARM_DESC(use_msi, "set 0 to use legacy interrupt");
 
 static unsigned int tx_bd_size_param = 32;
 module_param(tx_bd_size_param, uint, 0644);
-MODULE_PARM_DESC(tx_bd_size_param, "Tx descriptors queue size");
+MODULE_PARM_DESC(tx_bd_size_param, "Tx descriptors queue size, power of two");
 
 static unsigned int rx_bd_size_param = 256;
 module_param(rx_bd_size_param, uint, 0644);
-MODULE_PARM_DESC(rx_bd_size_param, "Rx descriptors queue size");
+MODULE_PARM_DESC(rx_bd_size_param, "Rx descriptors queue size, power of two");
 
 static u8 flashboot = 1;
 module_param(flashboot, byte, 0644);
@@ -509,6 +510,18 @@ static int qtnf_pcie_init_xfer(struct qtnf_pcie_bus_priv *priv)
        priv->rx_bd_w_index = 0;
        priv->rx_bd_r_index = 0;
 
+       if (!priv->tx_bd_num || !is_power_of_2(priv->tx_bd_num)) {
+               pr_err("tx_bd_size_param %u is not power of two\n",
+                      priv->tx_bd_num);
+               return -EINVAL;
+       }
+
+       if (!priv->rx_bd_num || !is_power_of_2(priv->rx_bd_num)) {
+               pr_err("rx_bd_size_param %u is not power of two\n",
+                      priv->rx_bd_num);
+               return -EINVAL;
+       }
+
        ret = alloc_skb_array(priv);
        if (ret) {
                pr_err("failed to allocate skb array\n");