From: françois romieu Date: Sun, 4 Dec 2011 20:30:52 +0000 (+0000) Subject: r8169: fix Rx index race between FIFO overflow recovery and NAPI handler. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c7c2c39be8ed4e503e987151f4599455060e219a;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git r8169: fix Rx index race between FIFO overflow recovery and NAPI handler. Since 92fc43b4159b518f5baae57301f26d770b0834c9, rtl8169_tx_timeout ends up resetting Rx and Tx indexes and thus racing with the NAPI handler via -> rtl8169_hw_reset -> rtl_hw_reset -> rtl8169_init_ring_indexes What about returning to the original state ? rtl_hw_reset is only used by rtl8169_hw_reset and rtl8169_init_one. The latter does not need rtl8169_init_ring_indexes because the indexes still contain their original values from the newly allocated network device private data area (i.e. 0). rtl8169_hw_reset is used by: 1. rtl8169_down Helper for rtl8169_close. rtl8169_open explicitely inits the indexes anyway. 2. rtl8169_pcierr_interrupt Indexes are set by rtl8169_reinit_task. 3. rtl8169_interrupt rtl8169_hw_reset is needed when the device goes down. See 1. 4. rtl_shutdown System shutdown handler. Indexes are irrelevant. 5. rtl8169_reset_task Indexes must be set before rtl_hw_start is called. 6. rtl8169_tx_timeout Indexes should not be set. This is the job of rtl8169_reset_task anyway. The removal of rtl8169_hw_reset in rtl8169_tx_timeout and its move in rtl8169_reset_task do not change the analysis. Signed-off-by: Francois Romieu Cc: hayeswang Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index 7a1e3a69f193..67bf07819992 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -3935,8 +3935,6 @@ static void rtl_hw_reset(struct rtl8169_private *tp) break; udelay(100); } - - rtl8169_init_ring_indexes(tp); } static int __devinit @@ -5395,14 +5393,16 @@ static void rtl8169_reset_task(struct work_struct *work) if (!netif_running(dev)) goto out_unlock; + rtl8169_hw_reset(tp); + rtl8169_wait_for_quiescence(dev); for (i = 0; i < NUM_RX_DESC; i++) rtl8169_mark_to_asic(tp->RxDescArray + i, rx_buf_sz); rtl8169_tx_clear(tp); + rtl8169_init_ring_indexes(tp); - rtl8169_hw_reset(tp); rtl_hw_start(dev); netif_wake_queue(dev); rtl8169_check_link_status(dev, tp, tp->mmio_addr); @@ -5413,11 +5413,6 @@ out_unlock: static void rtl8169_tx_timeout(struct net_device *dev) { - struct rtl8169_private *tp = netdev_priv(dev); - - rtl8169_hw_reset(tp); - - /* Let's wait a bit while any (async) irq lands on */ rtl8169_schedule_work(dev, rtl8169_reset_task); }