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authorLendacky, Thomas <Thomas.Lendacky@amd.com>2015-02-05 19:17:14 -0600
committerDavid S. Miller <davem@davemloft.net>2015-02-07 22:44:42 -0800
commitfd972b736bfec7e0297dac9501211abb91b436fd (patch)
tree4ae758cee05d2598d0940d11660d2ba1dbc2aeac /drivers/net
parent91e83133e70ebe1572746d1ad858b4eb28ab9b53 (diff)
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 <thomas.lendacky@amd.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/amd/xgbe/xgbe-drv.c11
1 files 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 e5ffb2ccb67..477a7e35d21 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);