[PATCH v2] mt76: mt7915: wed: find rx token by physical address

[PATCH v2] mt76: mt7915: wed: find rx token by physical address

[Shengyu Qu]

The token id in RxDMAD may be incorrect when it is not the last frame
due to WED HW bug. Lookup correct token id by physical address in sdp0.

Downstream patch link: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/737340322ab22b138fd200e020d61ffdbe3e36a9/autobuild/autobuild_5.4_mac80211_release/mt7988_wifi7_mac80211_mlo/package/kernel/mt76/patches/0062-mtk-wifi-mt76-mt7915-wed-find-rx-token-by-physical-a.patch

Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
Signed-off-by: Shengyu Qu <wiagn233@outlook.com>
---
Changes since v1:
 - Reordered code sequence to reversed Xmas tree order
 - Renamed some variables
---
 drivers/net/wireless/mediatek/mt76/dma.c | 26 +++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 844af16ee5513..25893686cbe85 100644
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -445,8 +445,32 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
 
 	if (mt76_queue_is_wed_rx(q)) {
 		u32 token = FIELD_GET(MT_DMA_CTL_TOKEN, buf1);
-		struct mt76_txwi_cache *t = mt76_rx_token_release(dev, token);
+		struct mt76_txwi_cache *t;
+		bool found = false;
+		u32 id;
+
+		if (*more) {
+			spin_lock_bh(&dev->rx_token_lock);
+
+			idr_for_each_entry(&dev->rx_token, t, id) {
+				if (t->dma_addr == le32_to_cpu(desc->buf0)) {
+					token = id;
+					found = 1;
+
+					/* Write correct id back to DMA*/
+					u32p_replace_bits(&buf1, id,
+							  MT_DMA_CTL_TOKEN);
+					WRITE_ONCE(desc->buf1, cpu_to_le32(buf1));
+					break;
+				}
+			}
+
+			spin_unlock_bh(&dev->rx_token_lock);
+			if (!found)
+				return NULL;
+		}
 
+		t = mt76_rx_token_release(dev, token);
 		if (!t)
 			return NULL;
 
-- 
2.48.1

RE: [PATCH v2] mt76: mt7915: wed: find rx token by physical address

[Ping-Ke Shih]

Shengyu Qu <wiagn233@outlook.com> wrote:
> The token id in RxDMAD may be incorrect when it is not the last frame
> due to WED HW bug. Lookup correct token id by physical address in sdp0.
> 
> Downstream patch link:
> https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/737340322ab22b138fd200e02
> 0d61ffdbe3e36a9/autobuild/autobuild_5.4_mac80211_release/mt7988_wifi7_mac80211_mlo/package/kernel/mt76
> /patches/0062-mtk-wifi-mt76-mt7915-wed-find-rx-token-by-physical-a.patch
> 
> Signed-off-by: Peter Chiu <chui-hao.chiu@mediatek.com>
> Signed-off-by: Shengyu Qu <wiagn233@outlook.com>
> ---
> Changes since v1:
>  - Reordered code sequence to reversed Xmas tree order
>  - Renamed some variables
> ---
>  drivers/net/wireless/mediatek/mt76/dma.c | 26 +++++++++++++++++++++++-
>  1 file changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
> index 844af16ee5513..25893686cbe85 100644
> --- a/drivers/net/wireless/mediatek/mt76/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/dma.c
> @@ -445,8 +445,32 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
> 
>         if (mt76_queue_is_wed_rx(q)) {
>                 u32 token = FIELD_GET(MT_DMA_CTL_TOKEN, buf1);
> -               struct mt76_txwi_cache *t = mt76_rx_token_release(dev, token);
> +               struct mt76_txwi_cache *t;
> +               bool found = false;
> +               u32 id;
> +
> +               if (*more) {
> +                       spin_lock_bh(&dev->rx_token_lock);
> +
> +                       idr_for_each_entry(&dev->rx_token, t, id) {
> +                               if (t->dma_addr == le32_to_cpu(desc->buf0)) {
> +                                       token = id;
> +                                       found = 1;

found = true;

Since you are digging how frequent this can occur, you may decide to have a
conversion function afterward, so it would be good to move this loop
into a function, like mt76_dma_get_id_from_txwi(dev, t). Then the you can
replace the implementation at that time.

By the way, I personally don't like so many indents. A function can ease
indents.

> +
> +                                       /* Write correct id back to DMA*/
> +                                       u32p_replace_bits(&buf1, id,
> +                                                         MT_DMA_CTL_TOKEN);
> +                                       WRITE_ONCE(desc->buf1, cpu_to_le32(buf1));
> +                                       break;
> +                               }
> +                       }
> +
> +                       spin_unlock_bh(&dev->rx_token_lock);
> +                       if (!found)
> +                               return NULL;
> +               }
> 
> +               t = mt76_rx_token_release(dev, token);
>                 if (!t)
>                         return NULL;
> 
> --
> 2.48.1