Commit 42cb27af authored by Shayne Chen's avatar Shayne Chen Committed by Felix Fietkau
Browse files

wifi: mt76: mt7996: fix RX buffer size of MCU event 



Some management frames are first processed by the firmware and then
passed to the driver through the MCU event rings. In CONNAC3, event rings
do not support scatter-gather and have a size limitation of 2048 bytes.
If a packet sized between 1728 and 2048 bytes arrives from an event ring,
the ring will hang because the driver attempts to use scatter-gather to
process it.

To fix this, include the size of struct skb_shared_info in the MCU RX
buffer size to prevent scatter-gather from being used for event skb in
mt76_dma_rx_fill_buf().

Fixes: 98686cd2 ("wifi: mt76: mt7996: add driver for MediaTek Wi-Fi 7 (802.11be) devices")
Co-developed-by: default avatarPeter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: default avatarPeter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: default avatarShayne Chen <shayne.chen@mediatek.com>
Link: https://patch.msgid.link/20250515032952.1653494-7-shayne.chen@mediatek.com


Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent 79e788fc

drivers/net/wireless/mediatek/mt76/mt7996/dma.c

+2 −2
Original line number Diff line number Diff line
@@ -531,7 +531,7 @@ int mt7996_dma_init(struct mt7996_dev *dev) 
	ret = mt76_queue_alloc(dev, &dev->mt76.q_rx[MT_RXQ_MCU],

			       MT_RXQ_ID(MT_RXQ_MCU),

			       MT7996_RX_MCU_RING_SIZE,

			       MT_RX_BUF_SIZE,

			       MT7996_RX_MCU_BUF_SIZE,

			       MT_RXQ_RING_BASE(MT_RXQ_MCU));

	if (ret)

		return ret;
@@ -540,7 +540,7 @@ int mt7996_dma_init(struct mt7996_dev *dev) 
	ret = mt76_queue_alloc(dev, &dev->mt76.q_rx[MT_RXQ_MCU_WA],

			       MT_RXQ_ID(MT_RXQ_MCU_WA),

			       MT7996_RX_MCU_RING_SIZE_WA,

			       MT_RX_BUF_SIZE,

			       MT7996_RX_MCU_BUF_SIZE,

			       MT_RXQ_RING_BASE(MT_RXQ_MCU_WA));

	if (ret)

		return ret;

drivers/net/wireless/mediatek/mt76/mt7996/mt7996.h

+3 −0
Original line number Diff line number Diff line
@@ -29,6 +29,9 @@ 
#define MT7996_RX_RING_SIZE		1536

#define MT7996_RX_MCU_RING_SIZE		512

#define MT7996_RX_MCU_RING_SIZE_WA	1024

/* scatter-gather of mcu event is not supported in connac3 */

#define MT7996_RX_MCU_BUF_SIZE		(2048 + \

					 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))



#define MT7996_DEVICE_ID		0x7990

#define MT7996_DEVICE_ID_2		0x7991