ag71xx: Fix rx ring buffer stall on small packets flood on qca956x and qca953x.
authorVittorio Gambaletta <openwrt@vittgam.net>
Sat, 25 Mar 2017 17:08:02 +0000 (18:08 +0100)
committerMatthias Schiffer <mschiffer@universe-factory.net>
Fri, 29 Dec 2017 14:17:07 +0000 (15:17 +0100)
Backported from Code Aurora QSDK

Signed-off-by: Vittorio Gambaletta <openwrt@vittgam.net>
target/linux/ar71xx/files/arch/mips/ath79/dev-eth.c
target/linux/ar71xx/files/arch/mips/include/asm/mach-ath79/ag71xx_platform.h
target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c

index a8b19b6..427de6a 100644 (file)
@@ -996,6 +996,9 @@ void __init ath79_register_eth(unsigned int id)
                        pdata->reset_bit = AR934X_RESET_GE0_MAC |
                                           AR934X_RESET_GE0_MDIO;
                        pdata->set_speed = ar934x_set_speed_ge0;
+
+                       if (ath79_soc == ATH79_SOC_QCA9533)
+                               pdata->disable_inline_checksum_engine = 1;
                } else {
                        pdata->reset_bit = AR934X_RESET_GE1_MAC |
                                           AR934X_RESET_GE1_MDIO;
@@ -1097,6 +1100,8 @@ void __init ath79_register_eth(unsigned int id)
                                pdata->set_speed = qca956x_set_speed_sgmii;
                        else
                                pdata->set_speed = ar934x_set_speed_ge0;
+
+                       pdata->disable_inline_checksum_engine = 1;
                } else {
                        pdata->reset_bit = QCA955X_RESET_GE1_MAC |
                                           QCA955X_RESET_GE1_MDIO;
index 078fa15..5fdc59c 100644 (file)
@@ -37,7 +37,7 @@ struct ag71xx_platform_data {
        u8              is_ar724x:1;
        u8              has_ar8216:1;
        u8              use_flow_control:1;
-       u8              is_qca956x:1;
+       u8              disable_inline_checksum_engine:1;
 
        struct ag71xx_switch_platform_data *switch_data;
 
index 566e951..72dd654 100644 (file)
@@ -629,6 +629,22 @@ __ag71xx_link_adjust(struct ag71xx *ag, bool update)
        ag71xx_wr(ag, AG71XX_REG_MAC_CFG2, cfg2);
        ag71xx_wr(ag, AG71XX_REG_FIFO_CFG5, fifo5);
        ag71xx_wr(ag, AG71XX_REG_MAC_IFCTL, ifctl);
+
+       if (pdata->disable_inline_checksum_engine) {
+               /*
+                * The rx ring buffer can stall on small packets on QCA953x and
+                * QCA956x. Disabling the inline checksum engine fixes the stall.
+                * The wr, rr functions cannot be used since this hidden register
+                * is outside of the normal ag71xx register block.
+                */
+               void __iomem *dam = ioremap_nocache(0xb90001bc, 0x4);
+               if (dam) {
+                       __raw_writel(__raw_readl(dam) & ~BIT(27), dam);
+                       (void)__raw_readl(dam);
+                       iounmap(dam);
+               }
+       }
+
        ag71xx_hw_start(ag);
 
        netif_carrier_on(ag->dev);