From: Deren Wu <deren.wu@xxxxxxxxxxxx> mt7921s driver may receive frames with fragment buffers. If there is a CTS packet received in monitor mode, the payload is 10 bytes only and need 6 bytes header padding after RXD buffer. However, only RXD in the first linear buffer, if we pull buffer size RXD-size+6 bytes with skb_pull(), that would trigger "BUG_ON(skb->len < skb->data_len)" in __skb_pull(). To avoid the nonlinear buffer issue, enlarge the RXD size from 128 to 136 to make sure all MCU operation in linear buffer. 136 = 128 + 8 128 : RXD size 8 : max header padding length [ 52.007562] kernel BUG at include/linux/skbuff.h:2313! [ 52.007578] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 52.007987] pc : skb_pull+0x48/0x4c [ 52.008015] lr : mt7921_queue_rx_skb+0x494/0x890 [mt7921_common] [ 52.008361] Call trace: [ 52.008377] skb_pull+0x48/0x4c [ 52.008400] mt76s_net_worker+0x134/0x1b0 [mt76_sdio 35339a92c6eb7d4bbcc806a1d22f56365565135c] [ 52.008431] __mt76_worker_fn+0xe8/0x170 [mt76 ef716597d11a77150bc07e3fdd68eeb0f9b56917] [ 52.008449] kthread+0x148/0x3ac [ 52.008466] ret_from_fork+0x10/0x30 Co-developed-by: Sean Wang <sean.wang@xxxxxxxxxxxx> Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx> Signed-off-by: Deren Wu <deren.wu@xxxxxxxxxxxx> --- drivers/net/wireless/mediatek/mt76/mt76.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h index 5e10fe156926..4f4ce3b3df54 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76.h +++ b/drivers/net/wireless/mediatek/mt76/mt76.h @@ -19,7 +19,8 @@ #define MT_MCU_RING_SIZE 32 #define MT_RX_BUF_SIZE 2048 -#define MT_SKB_HEAD_LEN 128 +/* 136 = 128+8. 128: RXD, 8:max header padding*/ +#define MT_SKB_HEAD_LEN 136 #define MT_MAX_NON_AQL_PKT 16 #define MT_TXQ_FREE_THR 32 -- 2.18.0
