Re: [PATCH v1] mt76: mt7915: wed: find rx token by physical address

From: Shengyu Qu
Date: Thu Mar 13 2025 - 08:43:47 EST


Hi Felix,

I'm not sure about the token ID incorrect frequency, this is just a port
of downstream patch, sorry.

Best regards,
Shengyu

在 2025/3/12 17:09, Felix Fietkau 写道:
On 12.03.25 02:41, Ping-Ke Shih wrote:
Shengyu Qu <wiagn233@xxxxxxxxxxx> wrote:

Hi Shih,

Can you also give this patch a review? Seems I also need to convert to
reverse Xmas tree order for this patch, will do it in next version.

Yes. Please do it.


Best regards,
Shengyu

在 2025/2/22 19:38, Shengyu Qu 写道:
> 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>
> ---
>   drivers/net/wireless/mediatek/mt76/dma.c | 25 +++++++++++++++++++ ++++-
>   1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/ net/wireless/mediatek/mt76/dma.c
> index 844af16ee551..5bf63014263c 100644
> --- a/drivers/net/wireless/mediatek/mt76/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/dma.c
> @@ -444,9 +444,32 @@ mt76_dma_get_buf(struct mt76_dev *dev, struct mt76_queue *q, int idx,
>       mt76_dma_should_drop_buf(drop, ctrl, buf1, desc_info);
>
>       if (mt76_queue_is_wed_rx(q)) {
> +        u32 id, find = 0;
>           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;
> +
> +        if (*more) {

Because of scope, should define 'find' (or 'found'?) as bool here.

> +            spin_lock_bh(&dev->rx_token_lock);
> +
> +            idr_for_each_entry(&dev->rx_token, t, id) {

idr_find() can only get a pointer associated with the ID. Not sure if it can
have a reverse way -- get ID from pointer. With sequential search in data path,
cost is higher.

Maybe you can consider to build association between argument 'idx' and
pointer/token by another patch.

But logic is okay to me.

Adding to that, it matters how frequently the token ID is incorrect. If the token ID is correct most of the time, then it's worth optimizing for that as the default case. In that case you should avoid the extra idr scan if the pointer for the provided token id already matches.

- Felix

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