From: Yan-Hsuan Chuang yhchuang@realtek.com
[ Upstream commit f4f84ff8377d4cedf18317747bc407b2cf657d0f ]
Sometimes the TX queue may be empty and we could possible dequeue a NULL pointer, crash the kernel. If the skb is NULL then there is nothing to do, just leave the ISR.
And the TX queue should not be empty here, so print an error to see if there is anything wrong for DMA ring.
Fixes: e3037485c68e ("rtw88: new Realtek 802.11ac driver") Signed-off-by: Yan-Hsuan Chuang yhchuang@realtek.com Signed-off-by: Kalle Valo kvalo@codeaurora.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/realtek/rtw88/pci.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index d90928be663b9..77a2bdee50fa7 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -762,6 +762,11 @@ static void rtw_pci_tx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci,
while (count--) { skb = skb_dequeue(&ring->queue); + if (!skb) { + rtw_err(rtwdev, "failed to dequeue %d skb TX queue %d, BD=0x%08x, rp %d -> %d\n", + count, hw_queue, bd_idx, ring->r.rp, cur_rp); + break; + } tx_data = rtw_pci_get_tx_data(skb); pci_unmap_single(rtwpci->pdev, tx_data->dma, skb->len, PCI_DMA_TODEVICE);