RE: [PATCH v2] mt76: mt7915: wed: find rx token by physical address
From: Ping-Ke Shih
Date: Thu Mar 13 2025 - 20:39:34 EST
Shengyu Qu <wiagn233@xxxxxxxxxxx> 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@xxxxxxxxxxxx>
> Signed-off-by: Shengyu Qu <wiagn233@xxxxxxxxxxx>
> ---
> 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