On Tue, Feb 19, 2019 at 01:19:26PM +0100, Felix Fietkau wrote:
> >> >> The way I see it, we have two choices.
> >> >> 1. Fix dwc2 to do its alignment quirk for the urb->sg != NULL case
> >> >> 2. Rely on urb->transfer_buffer and keep urb->sg NULL
> >> >
> >> > I agree, if this is only needed for dwc2. Though I would investigate
> >> > if this is not a bug on other platforms as well.
> >> >From what I can see, using Lorenzo's patches seems to be the better
> >> solution, since they avoid these corner cases in dwc2 (and maybe other
> >> drivers as well). I will apply them and then we'll see if we need to do
> >> any further improvements later on.
> >
> > They work on rpi dwc2, but they do not address root of the problem.
> > There is clearly something wrong how mt76usb handle SG, what is not
> > fixed. And adding disable_usb_sg module parameter for hcd's supporting
> > SG should be red flag.
> I think we're simply dealing with multiple issues here, only some of
> which are fixed by Lorenzo's patches.
> I'm pretty sure it's still wrong for mt76 to try to align its buffers,
> since the Linux USB API supports non-aligned transfer buffers and it
> should be up to the controller driver to deal with that.
Agree.
> dwc2 tries to do that, but that has limitations which I already pointed
> out and which are properly dealt with by Lorenzo's patches.
I planed to just accept current solution, but I started to work on patch
that remove len, sglen arguments from mt76u_buf_alloc() and use
q->buf_size and SKB_WITH_OVERHEAD(q->buf_size) directly and realized how
related code is now tangled.
Would be ok to send this patch with proper changelog as fix for RPI
against wireless-drivers and cc:stable (assuming it works and really
fix things on RPI) and revert Lorenzo's patches in -next ?
Stanislaw
>From 4f8d7d3f4031b0a97b3bb147cb7e52533886e7cc Mon Sep 17 00:00:00 2001
From: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
Date: Wed, 20 Feb 2019 13:29:42 +0100
Subject: [PATCH] mt76usb: use urb transfer_buffer for one segment
Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/mt76.h | 2 +
.../wireless/mediatek/mt76/mt76x02_usb_mcu.c | 4 +-
drivers/net/wireless/mediatek/mt76/usb.c | 75 +++++++++++--------
3 files changed, 46 insertions(+), 35 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
index 2e5bcb3fdff7..7e0680daeee6 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76.h
@@ -86,6 +86,8 @@ struct mt76_queue_buf {
struct mt76u_buf {
struct mt76_dev *dev;
struct urb *urb;
+ struct scatterlist *sg;
+ int num_sgs;
size_t len;
bool done;
};
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
index da299b8a1334..75561910d630 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_usb_mcu.c
@@ -90,7 +90,7 @@ static int mt76x02u_mcu_wait_resp(struct mt76_dev *dev, u8 seq)
if (urb->status)
return -EIO;
- data = sg_virt(&urb->sg[0]);
+ data = sg_virt(&buf->sg[0]);
if (usb->mcu.rp)
mt76x02u_multiple_mcu_reads(dev, data + 4,
urb->actual_length - 8);
@@ -266,7 +266,7 @@ static int
__mt76x02u_mcu_fw_send_data(struct mt76x02_dev *dev, struct mt76u_buf *buf,
const void *fw_data, int len, u32 dst_addr)
{
- u8 *data = sg_virt(&buf->urb->sg[0]);
+ u8 *data = sg_virt(&buf->sg[0]);
DECLARE_COMPLETION_ONSTACK(cmpl);
__le32 info;
u32 val;
diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index a1811c39415e..57bb16eaff06 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -277,7 +277,6 @@ mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76u_buf *buf,
int nsgs, int len, int sglen)
{
struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];
- struct urb *urb = buf->urb;
int i;
spin_lock_bh(&q->rx_page_lock);
@@ -292,21 +291,21 @@ mt76u_fill_rx_sg(struct mt76_dev *dev, struct mt76u_buf *buf,
page = virt_to_head_page(data);
offset = data - page_address(page);
- sg_set_page(&urb->sg[i], page, sglen, offset);
+ sg_set_page(&buf->sg[i], page, sglen, offset);
}
spin_unlock_bh(&q->rx_page_lock);
if (i < nsgs) {
int j;
- for (j = nsgs; j < urb->num_sgs; j++)
- skb_free_frag(sg_virt(&urb->sg[j]));
- urb->num_sgs = i;
+ for (j = nsgs; j < buf->num_sgs; j++)
+ skb_free_frag(sg_virt(&buf->sg[j]));
+ buf->num_sgs = i;
}
- urb->num_sgs = max_t(int, i, urb->num_sgs);
- buf->len = urb->num_sgs * sglen,
- sg_init_marker(urb->sg, urb->num_sgs);
+ buf->num_sgs = max_t(int, i, buf->num_sgs);
+ buf->len = buf->num_sgs * sglen,
+ sg_init_marker(buf->sg, buf->num_sgs);
return i ? : -ENOMEM;
}
@@ -318,13 +317,14 @@ int mt76u_buf_alloc(struct mt76_dev *dev, struct mt76u_buf *buf,
if (!buf->urb)
return -ENOMEM;
- buf->urb->sg = devm_kcalloc(dev->dev, nsgs, sizeof(*buf->urb->sg),
+ buf->sg = devm_kcalloc(dev->dev, nsgs, sizeof(*buf->sg),
gfp);
- if (!buf->urb->sg)
+ if (!buf->sg)
return -ENOMEM;
- sg_init_table(buf->urb->sg, nsgs);
+ sg_init_table(buf->sg, nsgs);
buf->dev = dev;
+ buf->num_sgs = nsgs;
return mt76u_fill_rx_sg(dev, buf, nsgs, len, sglen);
}
@@ -332,12 +332,11 @@ EXPORT_SYMBOL_GPL(mt76u_buf_alloc);
void mt76u_buf_free(struct mt76u_buf *buf)
{
- struct urb *urb = buf->urb;
struct scatterlist *sg;
int i;
- for (i = 0; i < urb->num_sgs; i++) {
- sg = &urb->sg[i];
+ for (i = 0; i < buf->num_sgs; i++) {
+ sg = &buf->sg[i];
if (!sg)
continue;
@@ -347,9 +346,10 @@ void mt76u_buf_free(struct mt76u_buf *buf)
}
EXPORT_SYMBOL_GPL(mt76u_buf_free);
-int mt76u_submit_buf(struct mt76_dev *dev, int dir, int index,
- struct mt76u_buf *buf, gfp_t gfp,
- usb_complete_t complete_fn, void *context)
+static void
+mt76u_fill_bulk_urb(struct mt76_dev *dev, int dir, int index,
+ struct mt76u_buf *buf, usb_complete_t complete_fn,
+ void *context)
{
struct usb_interface *intf = to_usb_interface(dev->dev);
struct usb_device *udev = interface_to_usbdev(intf);
@@ -360,9 +360,22 @@ int mt76u_submit_buf(struct mt76_dev *dev, int dir, int index,
else
pipe = usb_sndbulkpipe(udev, dev->usb.out_ep[index]);
- usb_fill_bulk_urb(buf->urb, udev, pipe, NULL, buf->len,
- complete_fn, context);
+ usb_fill_bulk_urb(buf->urb, udev, pipe, NULL, buf->len, complete_fn,
+ context);
+
+ if (buf->num_sgs > 1) {
+ buf->urb->num_sgs = buf->num_sgs;
+ buf->urb->sg = buf->sg;
+ } else {
+ buf->urb->transfer_buffer = sg_virt(buf->sg);
+ }
+}
+int mt76u_submit_buf(struct mt76_dev *dev, int dir, int index,
+ struct mt76u_buf *buf, gfp_t gfp,
+ usb_complete_t complete_fn, void *context)
+{
+ mt76u_fill_bulk_urb(dev, dir, index, buf, complete_fn, context);
return usb_submit_urb(buf->urb, gfp);
}
EXPORT_SYMBOL_GPL(mt76u_submit_buf);
@@ -672,7 +685,7 @@ static void mt76u_complete_tx(struct urb *urb)
}
static int
-mt76u_tx_build_sg(struct sk_buff *skb, struct urb *urb)
+mt76u_tx_build_sg(struct sk_buff *skb, struct mt76u_buf *buf)
{
int nsgs = 1 + skb_shinfo(skb)->nr_frags;
struct sk_buff *iter;
@@ -680,13 +693,14 @@ mt76u_tx_build_sg(struct sk_buff *skb, struct urb *urb)
skb_walk_frags(skb, iter)
nsgs += 1 + skb_shinfo(iter)->nr_frags;
- memset(urb->sg, 0, sizeof(*urb->sg) * MT_SG_MAX_SIZE);
+ memset(buf->sg, 0, sizeof(*buf->sg) * MT_SG_MAX_SIZE);
nsgs = min_t(int, MT_SG_MAX_SIZE, nsgs);
- sg_init_marker(urb->sg, nsgs);
- urb->num_sgs = nsgs;
+ sg_init_marker(buf->sg, nsgs);
+ buf->num_sgs = nsgs;
+ buf->len = skb->len;
- return skb_to_sgvec_nomark(skb, urb->sg, 0, skb->len);
+ return skb_to_sgvec_nomark(skb, buf->sg, 0, skb->len);
}
static int
@@ -694,12 +708,9 @@ mt76u_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q,
struct sk_buff *skb, struct mt76_wcid *wcid,
struct ieee80211_sta *sta)
{
- struct usb_interface *intf = to_usb_interface(dev->dev);
- struct usb_device *udev = interface_to_usbdev(intf);
u8 ep = q2ep(q->hw_idx);
struct mt76u_buf *buf;
u16 idx = q->tail;
- unsigned int pipe;
int err;
if (q->queued == q->ndesc)
@@ -712,13 +723,11 @@ mt76u_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q,
buf = &q->entry[idx].ubuf;
buf->done = false;
- err = mt76u_tx_build_sg(skb, buf->urb);
+ err = mt76u_tx_build_sg(skb, buf);
if (err < 0)
return err;
- pipe = usb_sndbulkpipe(udev, dev->usb.out_ep[ep]);
- usb_fill_bulk_urb(buf->urb, udev, pipe, NULL, skb->len,
- mt76u_complete_tx, buf);
+ mt76u_fill_bulk_urb(dev, USB_DIR_OUT, ep, buf, mt76u_complete_tx, buf);
q->tail = (q->tail + 1) % q->ndesc;
q->entry[idx].skb = skb;
@@ -776,8 +785,8 @@ static int mt76u_alloc_tx(struct mt76_dev *dev)
if (!buf->urb)
return -ENOMEM;
- buf->urb->sg = devm_kzalloc(dev->dev, size, GFP_KERNEL);
- if (!buf->urb->sg)
+ buf->sg = devm_kzalloc(dev->dev, size, GFP_KERNEL);
+ if (!buf->sg)
return -ENOMEM;
}
}
--
2.20.1
