2021-03-04 17:28:15

by Sean Wang

[permalink] [raw]

Subject: [PATCH 2/3] mt76: mt7663s: make all of packets 4-bytes aligned in sdio tx aggregation

---

From: Sean Wang <[email protected]>

Each packet should be padded with the additional zero to become 4-bytes
alignment in sdio tx aggregation.

Fixes: 1522ff731f84 ("mt76: mt7663s: introduce sdio tx aggregation")
Signed-off-by: Sean Wang <[email protected]>
---
drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
index 9fb506f2ace6..2d3b7d1e2c92 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
@@ -218,6 +218,7 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
int qid, err, nframes = 0, len = 0, pse_sz = 0, ple_sz = 0;
bool mcu = q == dev->q_mcu[MT_MCUQ_WM];
struct mt76_sdio *sdio = &dev->sdio;
+ u8 pad;

qid = mcu ? ARRAY_SIZE(sdio->xmit_buf) - 1 : q->qid;
while (q->first != q->head) {
@@ -234,7 +235,8 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
goto next;
}

- if (len + e->skb->len + 4 > MT76S_XMIT_BUF_SZ)
+ pad = roundup(e->skb->len, 4) - e->skb->len;
+ if (len + e->skb->len + pad + 4 > MT76S_XMIT_BUF_SZ)
break;

if (mt7663s_tx_pick_quota(sdio, mcu, e->buf_sz, &pse_sz,
@@ -252,6 +254,9 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
len += iter->len;
nframes++;
}
+
+ memset(sdio->xmit_buf[qid] + len, 0, pad);
+ len += pad;
next:
q->first = (q->first + 1) % q->ndesc;
e->done = true;
--
2.25.1

2021-03-04 17:29:48

by Lorenzo Bianconi

[permalink] [raw]

Subject: Re: [PATCH 2/3] mt76: mt7663s: make all of packets 4-bytes aligned in sdio tx aggregation

---

> From: Sean Wang <[email protected]>
>
> Each packet should be padded with the additional zero to become 4-bytes
> alignment in sdio tx aggregation.
>
> Fixes: 1522ff731f84 ("mt76: mt7663s: introduce sdio tx aggregation")
> Signed-off-by: Sean Wang <[email protected]>
> ---
> drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c b/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
> index 9fb506f2ace6..2d3b7d1e2c92 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7615/sdio_txrx.c
> @@ -218,6 +218,7 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
> int qid, err, nframes = 0, len = 0, pse_sz = 0, ple_sz = 0;
> bool mcu = q == dev->q_mcu[MT_MCUQ_WM];
> struct mt76_sdio *sdio = &dev->sdio;
> + u8 pad;
>
> qid = mcu ? ARRAY_SIZE(sdio->xmit_buf) - 1 : q->qid;
> while (q->first != q->head) {
> @@ -234,7 +235,8 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
> goto next;
> }
>
> - if (len + e->skb->len + 4 > MT76S_XMIT_BUF_SZ)
> + pad = roundup(e->skb->len, 4) - e->skb->len;
> + if (len + e->skb->len + pad + 4 > MT76S_XMIT_BUF_SZ)
> break;
>
> if (mt7663s_tx_pick_quota(sdio, mcu, e->buf_sz, &pse_sz,
> @@ -252,6 +254,9 @@ static int mt7663s_tx_run_queue(struct mt76_dev *dev, struct mt76_queue *q)
> len += iter->len;
> nframes++;
> }
> +
> + memset(sdio->xmit_buf[qid] + len, 0, pad);
> + len += pad;

maybe it is better to do something like:

if (unlikely(pad)) {
memset(sdio->xmit_buf[qid] + len, 0, pad);
len += pad;
}

Regards,
Lorenzo

> next:
> q->first = (q->first + 1) % q->ndesc;
> e->done = true;
> --
> 2.25.1

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