From fd972b736bfec7e0297dac9501211abb91b436fd Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Thu, 5 Feb 2015 19:17:14 -0600 Subject: [PATCH] amd-xgbe: Check per channel DMA interrupt use in main ISR When using per channel DMA interrupts the transmit interrupt (TI) and the receive interrupt (RI) are masked off so as to not generate an interrupt to the main ISR. However, should another interrupt fire for the DMA channel that is handled by the main ISR the TI/RI bits can still be set. This will cause the wrong and uninitialized napi structure to be used causing a panic. Add a check to be sure per channel DMA interrupts are not enabled before acting on those bit flags. Signed-off-by: Tom Lendacky Signed-off-by: David S. Miller --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index e5ffb2ccb67d..477a7e35d21a 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -337,12 +337,13 @@ static irqreturn_t xgbe_isr(int irq, void *data) dma_ch_isr = XGMAC_DMA_IOREAD(channel, DMA_CH_SR); DBGPR(" DMA_CH%u_ISR = %08x\n", i, dma_ch_isr); - /* If we get a TI or RI interrupt that means per channel DMA - * interrupts are not enabled, so we use the private data napi - * structure, not the per channel napi structure + /* The TI or RI interrupt bits may still be set even if using + * per channel DMA interrupts. Check to be sure those are not + * enabled before using the private data napi structure. */ - if (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, TI) || - XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, RI)) { + if (!pdata->per_channel_irq && + (XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, TI) || + XGMAC_GET_BITS(dma_ch_isr, DMA_CH_SR, RI))) { if (napi_schedule_prep(&pdata->napi)) { /* Disable Tx and Rx interrupts */ xgbe_disable_rx_tx_ints(pdata); -- 2.20.1