> On 21.12.22 14:10, Mikhail Gavrilov wrote:
> > On Wed, Dec 21, 2022 at 3:45 PM Felix Fietkau <nbd@xxxxxxxx> wrote:
> > >
> > > I'm pretty sure that commit is unrelated to this issue. However, while
> > > looking at the code I found a bug that would explain your issue.
> > >
> > > Please try this patch:
> > > ---
> > > --- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c
> > > +++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
> > > @@ -422,15 +422,15 @@ void mt7921_roc_timer(struct timer_list *timer)
> > >
> > > static int mt7921_abort_roc(struct mt7921_phy *phy, struct mt7921_vif *vif)
> > > {
> > > - int err;
> > > -
> > > - if (!test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state))
> > > - return 0;
> > > + int err = 0;
> > >
> > > del_timer_sync(&phy->roc_timer);
> > > cancel_work_sync(&phy->roc_work);
> > > - err = mt7921_mcu_abort_roc(phy, vif, phy->roc_token_id);
> > > - clear_bit(MT76_STATE_ROC, &phy->mt76->state);
> > > +
> > > + mt7921_mutex_acquire(phy->dev);
> > > + if (test_and_clear_bit(MT76_STATE_ROC, &phy->mt76->state))
> > > + err = mt7921_mcu_abort_roc(phy, vif, phy->roc_token_id);
> > > + mt7921_mutex_release(phy->dev);
> > >
> > > return err;
> > > }
> > > @@ -487,13 +487,8 @@ static int mt7921_cancel_remain_on_channel(struct ieee80211_hw *hw,
> > > {
> > > struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
> > > struct mt7921_phy *phy = mt7921_hw_phy(hw);
> > > - int err;
> > >
> > > - mt7921_mutex_acquire(phy->dev);
> > > - err = mt7921_abort_roc(phy, mvif);
> > > - mt7921_mutex_release(phy->dev);
> > > -
> > > - return err;
> > > + return mt7921_abort_roc(phy, mvif);
> > > }
> > >
> > > static int mt7921_set_channel(struct mt7921_phy *phy)
> > > @@ -1778,11 +1773,8 @@ static void mt7921_mgd_complete_tx(struct ieee80211_hw *hw,
> > > struct ieee80211_prep_tx_info *info)
> > > {
> > > struct mt7921_vif *mvif = (struct mt7921_vif *)vif->drv_priv;
> > > - struct mt7921_dev *dev = mt7921_hw_dev(hw);
> > >
> > > - mt7921_mutex_acquire(dev);
> > > mt7921_abort_roc(mvif->phy, mvif);
> > > - mt7921_mutex_release(dev);
> > > }
> > >
> > > const struct ieee80211_ops mt7921_ops = {
> > >
> >
> > Unfortunately this patch did not fix the issue.
> > There are still many messages in the logs "mt7921e 0000:05:00.0:
> > AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x0010 address=0xffdc6a80
> > flags=0x0050]"
> Thanks! I guess I focused on the wrong part of your kernel log
> initially. After more code review, I found that there is in fact a DMA
> related bug in the commit that your bisection pointed to, which happened
> to uncover and trigger the deadlock fixed by my other patch.
>
> So here's my fix for the DMA issue:
Thx for fixing this issue, I tested the patch with mt7986 w and w/o WED enabled and it works
fine.
Tested-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> ---
> --- a/drivers/net/wireless/mediatek/mt76/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/dma.c
> @@ -205,6 +205,52 @@ mt76_dma_queue_reset(struct mt76_dev *dev, struct mt76_queue *q)
> mt76_dma_sync_idx(dev, q);
> }
> +static int
> +mt76_dma_add_rx_buf(struct mt76_dev *dev, struct mt76_queue *q,
> + struct mt76_queue_buf *buf, void *data)
> +{
> + struct mt76_desc *desc = &q->desc[q->head];
> + struct mt76_queue_entry *entry = &q->entry[q->head];
> + struct mt76_txwi_cache *txwi = NULL;
> + u32 buf1 = 0, ctrl;
> + int idx = q->head;
> + int rx_token;
> +
> + ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len);
> +
> + if ((q->flags & MT_QFLAG_WED) &&
> + FIELD_GET(MT_QFLAG_WED_TYPE, q->flags) == MT76_WED_Q_RX) {
> + txwi = mt76_get_rxwi(dev);
> + if (!txwi)
> + return -ENOMEM;
> +
> + rx_token = mt76_rx_token_consume(dev, data, txwi, buf->addr);
> + if (rx_token < 0) {
> + mt76_put_rxwi(dev, txwi);
> + return -ENOMEM;
> + }
> +
> + buf1 |= FIELD_PREP(MT_DMA_CTL_TOKEN, rx_token);
> + ctrl |= MT_DMA_CTL_TO_HOST;
> + }
> +
> + WRITE_ONCE(desc->buf0, cpu_to_le32(buf->addr));
> + WRITE_ONCE(desc->buf1, cpu_to_le32(buf1));
> + WRITE_ONCE(desc->ctrl, cpu_to_le32(ctrl));
> + WRITE_ONCE(desc->info, 0);
> +
> + entry->dma_addr[0] = buf->addr;
> + entry->dma_len[0] = buf->len;
> + entry->txwi = txwi;
> + entry->buf = data;
> + entry->wcid = 0xffff;
> + entry->skip_buf1 = true;
> + q->head = (q->head + 1) % q->ndesc;
> + q->queued++;
> +
> + return idx;
> +}
> +
> static int
> mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
> struct mt76_queue_buf *buf, int nbufs, u32 info,
> @@ -215,6 +261,11 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
> int i, idx = -1;
> u32 ctrl, next;
> + if (txwi) {
> + q->entry[q->head].txwi = DMA_DUMMY_DATA;
> + q->entry[q->head].skip_buf0 = true;
> + }
> +
> for (i = 0; i < nbufs; i += 2, buf += 2) {
> u32 buf0 = buf[0].addr, buf1 = 0;
> @@ -224,51 +275,28 @@ mt76_dma_add_buf(struct mt76_dev *dev, struct mt76_queue *q,
> desc = &q->desc[idx];
> entry = &q->entry[idx];
> - if ((q->flags & MT_QFLAG_WED) &&
> - FIELD_GET(MT_QFLAG_WED_TYPE, q->flags) == MT76_WED_Q_RX) {
> - struct mt76_txwi_cache *t = txwi;
> - int rx_token;
> -
> - if (!t)
> - return -ENOMEM;
> -
> - rx_token = mt76_rx_token_consume(dev, (void *)skb, t,
> - buf[0].addr);
> - if (rx_token < 0)
> - return -ENOMEM;
> -
> - buf1 |= FIELD_PREP(MT_DMA_CTL_TOKEN, rx_token);
> - ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len) |
> - MT_DMA_CTL_TO_HOST;
> - } else {
> - if (txwi) {
> - q->entry[next].txwi = DMA_DUMMY_DATA;
> - q->entry[next].skip_buf0 = true;
> - }
> -
> - if (buf[0].skip_unmap)
> - entry->skip_buf0 = true;
> - entry->skip_buf1 = i == nbufs - 1;
> -
> - entry->dma_addr[0] = buf[0].addr;
> - entry->dma_len[0] = buf[0].len;
> -
> - ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len);
> - if (i < nbufs - 1) {
> - entry->dma_addr[1] = buf[1].addr;
> - entry->dma_len[1] = buf[1].len;
> - buf1 = buf[1].addr;
> - ctrl |= FIELD_PREP(MT_DMA_CTL_SD_LEN1, buf[1].len);
> - if (buf[1].skip_unmap)
> - entry->skip_buf1 = true;
> - }
> -
> - if (i == nbufs - 1)
> - ctrl |= MT_DMA_CTL_LAST_SEC0;
> - else if (i == nbufs - 2)
> - ctrl |= MT_DMA_CTL_LAST_SEC1;
> + if (buf[0].skip_unmap)
> + entry->skip_buf0 = true;
> + entry->skip_buf1 = i == nbufs - 1;
> +
> + entry->dma_addr[0] = buf[0].addr;
> + entry->dma_len[0] = buf[0].len;
> +
> + ctrl = FIELD_PREP(MT_DMA_CTL_SD_LEN0, buf[0].len);
> + if (i < nbufs - 1) {
> + entry->dma_addr[1] = buf[1].addr;
> + entry->dma_len[1] = buf[1].len;
> + buf1 = buf[1].addr;
> + ctrl |= FIELD_PREP(MT_DMA_CTL_SD_LEN1, buf[1].len);
> + if (buf[1].skip_unmap)
> + entry->skip_buf1 = true;
> }
> + if (i == nbufs - 1)
> + ctrl |= MT_DMA_CTL_LAST_SEC0;
> + else if (i == nbufs - 2)
> + ctrl |= MT_DMA_CTL_LAST_SEC1;
> +
> WRITE_ONCE(desc->buf0, cpu_to_le32(buf0));
> WRITE_ONCE(desc->buf1, cpu_to_le32(buf1));
> WRITE_ONCE(desc->info, cpu_to_le32(info));
> @@ -567,17 +595,9 @@ mt76_dma_rx_fill(struct mt76_dev *dev, struct mt76_queue *q)
> spin_lock_bh(&q->lock);
> while (q->queued < q->ndesc - 1) {
> - struct mt76_txwi_cache *t = NULL;
> struct mt76_queue_buf qbuf;
> void *buf = NULL;
> - if ((q->flags & MT_QFLAG_WED) &&
> - FIELD_GET(MT_QFLAG_WED_TYPE, q->flags) == MT76_WED_Q_RX) {
> - t = mt76_get_rxwi(dev);
> - if (!t)
> - break;
> - }
> -
> buf = page_frag_alloc(&q->rx_page, q->buf_size, GFP_ATOMIC);
> if (!buf)
> break;
> @@ -591,7 +611,7 @@ mt76_dma_rx_fill(struct mt76_dev *dev, struct mt76_queue *q)
> qbuf.addr = addr + offset;
> qbuf.len = len - offset;
> qbuf.skip_unmap = false;
> - if (mt76_dma_add_buf(dev, q, &qbuf, 1, 0, buf, t) < 0) {
> + if (mt76_dma_add_rx_buf(dev, q, &qbuf, buf) < 0) {
> dma_unmap_single(dev->dma_dev, addr, len,
> DMA_FROM_DEVICE);
> skb_free_frag(buf);
>
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