wcn36xx: Put DXE block into reset before freeing memory

[ Upstream commit ed04ea76e69e7194f7489cebe23a32a68f39218d ]

When deiniting the DXE hardware we should reset the block to ensure there
is no spurious DMA write transaction from the downstream WCNSS to upstream
MSM at a skbuff address we will have released.

Fixes: 8e84c2582169 ("wcn36xx: mac80211 driver for Qualcomm WCN3660/WCN3680 hardware")
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20211105122152.1580542-4-bryan.odonoghue@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/ath/wcn36xx/dxe.c
index 017c7d78072baf2cf2f839bb82bd2f47be7c867f..e1a35c2eadb6c305c0f216d2612b2ce282563ee7 100644 (file)
--- a/drivers/net/wireless/ath/wcn36xx/dxe.c
+++ b/drivers/net/wireless/ath/wcn36xx/dxe.c
@@ -997,6 +997,8 @@ out_err_txh_ch:
 
 void wcn36xx_dxe_deinit(struct wcn36xx *wcn)
 {
+       int reg_data = 0;
+
        /* Disable channel interrupts */
        wcn36xx_dxe_disable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_H);
        wcn36xx_dxe_disable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_L);
@@ -1012,6 +1014,10 @@ void wcn36xx_dxe_deinit(struct wcn36xx *wcn)
                wcn->tx_ack_skb = NULL;
        }
 
+       /* Put the DXE block into reset before freeing memory */
+       reg_data = WCN36XX_DXE_REG_RESET;
+       wcn36xx_dxe_write_register(wcn, WCN36XX_DXE_REG_CSR_RESET, reg_data);
+
        wcn36xx_dxe_ch_free_skbs(wcn, &wcn->dxe_rx_l_ch);
        wcn36xx_dxe_ch_free_skbs(wcn, &wcn->dxe_rx_h_ch);