Patch "wcn36xx: Fix DMA channel enable/disable cycle" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    wcn36xx: Fix DMA channel enable/disable cycle

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     wcn36xx-fix-dma-channel-enable-disable-cycle.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 5edc1570dc3eec7b5d7f1bcc2354835cdb7c5961
Author: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
Date:   Fri Nov 5 12:21:50 2021 +0000

    wcn36xx: Fix DMA channel enable/disable cycle
    
    [ Upstream commit 89dcb1da611d9b3ff0728502d58372fdaae9ebff ]
    
    Right now we have a broken sequence where we enable DMA channel interrupts
    which can be left enabled and never disabled if we hit an error path.
    
    Worse still when we unload the driver, the DMA channel interrupt bits are
    left intact. About the only saving grace here is that we do remember to
    disable the wcnss interrupt when unload the driver.
    
    Fixes: 8e84c2582169 ("wcn36xx: mac80211 driver for Qualcomm WCN3660/WCN3680 hardware")
    Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
    Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20211105122152.1580542-2-bryan.odonoghue@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/wireless/ath/wcn36xx/dxe.c b/drivers/net/wireless/ath/wcn36xx/dxe.c
index cf4eb0fb28151..0909d0c423cbb 100644
--- a/drivers/net/wireless/ath/wcn36xx/dxe.c
+++ b/drivers/net/wireless/ath/wcn36xx/dxe.c
@@ -272,6 +272,21 @@ static int wcn36xx_dxe_enable_ch_int(struct wcn36xx *wcn, u16 wcn_ch)
 	return 0;
 }
 
+static void wcn36xx_dxe_disable_ch_int(struct wcn36xx *wcn, u16 wcn_ch)
+{
+	int reg_data = 0;
+
+	wcn36xx_dxe_read_register(wcn,
+				  WCN36XX_DXE_INT_MASK_REG,
+				  &reg_data);
+
+	reg_data &= ~wcn_ch;
+
+	wcn36xx_dxe_write_register(wcn,
+				   WCN36XX_DXE_INT_MASK_REG,
+				   (int)reg_data);
+}
+
 static int wcn36xx_dxe_fill_skb(struct device *dev,
 				struct wcn36xx_dxe_ctl *ctl,
 				gfp_t gfp)
@@ -869,7 +884,6 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 		WCN36XX_DXE_WQ_TX_L);
 
 	wcn36xx_dxe_read_register(wcn, WCN36XX_DXE_REG_CH_EN, &reg_data);
-	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_L);
 
 	/***************************************/
 	/* Init descriptors for TX HIGH channel */
@@ -893,9 +907,6 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 
 	wcn36xx_dxe_read_register(wcn, WCN36XX_DXE_REG_CH_EN, &reg_data);
 
-	/* Enable channel interrupts */
-	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_H);
-
 	/***************************************/
 	/* Init descriptors for RX LOW channel */
 	/***************************************/
@@ -905,7 +916,6 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 		goto out_err_rxl_ch;
 	}
 
-
 	/* For RX we need to preallocated buffers */
 	wcn36xx_dxe_ch_alloc_skb(wcn, &wcn->dxe_rx_l_ch);
 
@@ -928,9 +938,6 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 		WCN36XX_DXE_REG_CTL_RX_L,
 		WCN36XX_DXE_CH_DEFAULT_CTL_RX_L);
 
-	/* Enable channel interrupts */
-	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_L);
-
 	/***************************************/
 	/* Init descriptors for RX HIGH channel */
 	/***************************************/
@@ -962,15 +969,18 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 		WCN36XX_DXE_REG_CTL_RX_H,
 		WCN36XX_DXE_CH_DEFAULT_CTL_RX_H);
 
-	/* Enable channel interrupts */
-	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_H);
-
 	ret = wcn36xx_dxe_request_irqs(wcn);
 	if (ret < 0)
 		goto out_err_irq;
 
 	timer_setup(&wcn->tx_ack_timer, wcn36xx_dxe_tx_timer, 0);
 
+	/* Enable channel interrupts */
+	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_L);
+	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_H);
+	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_L);
+	wcn36xx_dxe_enable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_RX_H);
+
 	return 0;
 
 out_err_irq:
@@ -987,6 +997,12 @@ int wcn36xx_dxe_init(struct wcn36xx *wcn)
 
 void wcn36xx_dxe_deinit(struct wcn36xx *wcn)
 {
+	/* 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);
+	wcn36xx_dxe_disable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_H);
+	wcn36xx_dxe_disable_ch_int(wcn, WCN36XX_INT_MASK_CHAN_TX_L);
+
 	free_irq(wcn->tx_irq, wcn);
 	free_irq(wcn->rx_irq, wcn);
 	del_timer(&wcn->tx_ack_timer);