[PATCH] b43: use rx desc underrun interrupt
Thommy
thommyj at gmail.com
Sat Apr 20 10:14:09 EDT 2013
Hi,
new try sending in the patch (with pine instead of gmail webclient this
time). Patch created on latest wireless-testing
BR,
Thommy Jakobsson
Signed-off-by: Thommy Jakobsson <thommyj at gmail.com>
---
drivers/net/wireless/b43/b43.h | 1 +
drivers/net/wireless/b43/dma.c | 16 +++++++++++++++
drivers/net/wireless/b43/dma.h | 4 +++-
drivers/net/wireless/b43/main.c | 43 ++++++++++++++++-----------------------
4 files changed, 38 insertions(+), 26 deletions(-)
diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 7f3d461..fdcd00f 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -680,6 +680,7 @@ struct b43_noise_calculation {
struct b43_stats {
u8 link_noise;
+ u32 rxdesc_underruns;
};
struct b43_key {
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index 1221469..2ae00dd 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -1733,6 +1733,22 @@ drop_recycle_buffer:
sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
}
+void b43_dma_rx_discard(struct b43_dmaring *ring)
+{
+ B43_WARN_ON(ring->tx);
+
+ /* Device has filled all buffers, drop all packets in buffers
+ * and let TCP decrease speed.
+ * Set index to one desc after the last one
+ * so the device will see all slots as free again
+ */
+ /*
+ *TODO: How to increase rx_drop in mac80211?
+ */
+ b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
+ sizeof(struct b43_dmadesc32));
+}
+
void b43_dma_rx(struct b43_dmaring *ring)
{
const struct b43_dma_ops *ops = ring->ops;
diff --git a/drivers/net/wireless/b43/dma.h b/drivers/net/wireless/b43/dma.h
index 9fdd198..fed8163 100644
--- a/drivers/net/wireless/b43/dma.h
+++ b/drivers/net/wireless/b43/dma.h
@@ -9,7 +9,7 @@
/* DMA-Interrupt reasons. */
#define B43_DMAIRQ_FATALMASK ((1 << 10) | (1 << 11) | (1 << 12) \
| (1 << 14) | (1 << 15))
-#define B43_DMAIRQ_NONFATALMASK (1 << 13)
+#define B43_DMAIRQ_RDESC_UFLOW (1 << 13)
#define B43_DMAIRQ_RX_DONE (1 << 16)
/*** 32-bit DMA Engine. ***/
@@ -295,6 +295,8 @@ int b43_dma_tx(struct b43_wldev *dev,
void b43_dma_handle_txstatus(struct b43_wldev *dev,
const struct b43_txstatus *status);
+void b43_dma_rx_discard(struct b43_dmaring *ring);
+
void b43_dma_rx(struct b43_dmaring *ring);
void b43_dma_direct_fifo_rx(struct b43_wldev *dev,
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index d377f77..277fe75 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -1902,30 +1902,19 @@ static void b43_do_interrupt_thread(struct b43_wldev *dev)
}
}
- if (unlikely(merged_dma_reason & (B43_DMAIRQ_FATALMASK |
- B43_DMAIRQ_NONFATALMASK))) {
- if (merged_dma_reason & B43_DMAIRQ_FATALMASK) {
- b43err(dev->wl, "Fatal DMA error: "
- "0x%08X, 0x%08X, 0x%08X, "
- "0x%08X, 0x%08X, 0x%08X\n",
- dma_reason[0], dma_reason[1],
- dma_reason[2], dma_reason[3],
- dma_reason[4], dma_reason[5]);
- b43err(dev->wl, "This device does not support DMA "
+ if (unlikely(merged_dma_reason & (B43_DMAIRQ_FATALMASK))) {
+ b43err(dev->wl, "Fatal DMA error: "
+ "0x%08X, 0x%08X, 0x%08X, "
+ "0x%08X, 0x%08X, 0x%08X\n",
+ dma_reason[0], dma_reason[1],
+ dma_reason[2], dma_reason[3],
+ dma_reason[4], dma_reason[5]);
+ b43err(dev->wl, "This device does not support DMA "
"on your system. It will now be switched to PIO.\n");
- /* Fall back to PIO transfers if we get fatal DMA errors! */
- dev->use_pio = true;
- b43_controller_restart(dev, "DMA error");
- return;
- }
- if (merged_dma_reason & B43_DMAIRQ_NONFATALMASK) {
- b43err(dev->wl, "DMA error: "
- "0x%08X, 0x%08X, 0x%08X, "
- "0x%08X, 0x%08X, 0x%08X\n",
- dma_reason[0], dma_reason[1],
- dma_reason[2], dma_reason[3],
- dma_reason[4], dma_reason[5]);
- }
+ /* Fall back to PIO transfers if we get fatal DMA errors! */
+ dev->use_pio = true;
+ b43_controller_restart(dev, "DMA error");
+ return;
}
if (unlikely(reason & B43_IRQ_UCODE_DEBUG))
@@ -1944,6 +1933,10 @@ static void b43_do_interrupt_thread(struct b43_wldev *dev)
handle_irq_noise(dev);
/* Check the DMA reason registers for received data. */
+ if (dma_reason[0] & B43_DMAIRQ_RDESC_UFLOW) {
+ b43warn(dev->wl, "RX descriptor underrun, dropping packets\n");
+ b43_dma_rx_discard(dev->dma.rx_ring);
+ }
if (dma_reason[0] & B43_DMAIRQ_RX_DONE) {
if (b43_using_pio_transfers(dev))
b43_pio_rx(dev->pio.rx_queue);
@@ -2001,7 +1994,7 @@ static irqreturn_t b43_do_interrupt(struct b43_wldev *dev)
return IRQ_NONE;
dev->dma_reason[0] = b43_read32(dev, B43_MMIO_DMA0_REASON)
- & 0x0001DC00;
+ & 0x0001FC00;
dev->dma_reason[1] = b43_read32(dev, B43_MMIO_DMA1_REASON)
& 0x0000DC00;
dev->dma_reason[2] = b43_read32(dev, B43_MMIO_DMA2_REASON)
@@ -3130,7 +3123,7 @@ static int b43_chip_init(struct b43_wldev *dev)
b43_write32(dev, 0x018C, 0x02000000);
}
b43_write32(dev, B43_MMIO_GEN_IRQ_REASON, 0x00004000);
- b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001DC00);
+ b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001FC00);
b43_write32(dev, B43_MMIO_DMA1_IRQ_MASK, 0x0000DC00);
b43_write32(dev, B43_MMIO_DMA2_IRQ_MASK, 0x0000DC00);
b43_write32(dev, B43_MMIO_DMA3_IRQ_MASK, 0x0001DC00);
--
1.7.9.5
On Fri, 19 Apr 2013, Jonas Gorski wrote:
> Hi,
>
> On Mon, Apr 15, 2013 at 10:02 AM, Thommy Jakobsson <thommyj at gmail.com> wrote:
> > Hi,
> >
> > long user of b43 driver under openwrt. Not sure if it has been posted
> > previously but using slow and old hardware (as routers running openwrt
> > most of the time is), the CPU is sometimes slower than the NIC. So
> > recently I, and several others, has had problem of wifi going down.
> > See ticket 7552 at openwrt for more info
> > (https://dev.openwrt.org/ticket/7552)
> >
> > I have tracked down the problem to the nic getting into a rx
> > descriptor underrun. Since the driver don't listen to that (or take
> > care of it in any other way), the Wifi seemingly just dies. The CPU is
> > waiting for data from the nic and the nic is waiting for a
> > confirmation that it can keep sending.
> >
> > I created a patch for handling of that interrupt. I have tested it by
> > reducing the number of rx slots to 16 and sending a couple of 100GB of
> > data. Previously Wifi went down within a minute when maxing out the
> > uplink (so rx for AP), now it has been working flawless for a 1.5week.
>
> Nice, very good to hear. Looks like you found the real issue the rx
> descriptor count increase was just papering over. Some comments
> regarding your patch.
>
> >
> > BR,
> > Thommy Jakobsson
> >
>
> You are missing a "Signed-off-by" - without it the patch can never be
> accepted. Also your patch is has broken tabs (they were converted to
> spaces), as well as is line-broken, so it doesn't apply anymore. You
> can't use gmail's web interface for sending patches.
>
> > Index: drivers/net/wireless/b43/dma.c
> > ===================================================================
> > --- compat-wireless-2012-09-07.orig/drivers/net/wireless/b43/dma.c
> > 2013-04-09 17:33:54.325322046 +0200
> > +++ compat-wireless-2012-09-07/drivers/net/wireless/b43/dma.c
>
> You should make your patch against the newest git tree, so usually
> wireless-testing or Rafał's b43-next.
>
> > 2013-04-09 17:34:43.473565843 +0200
> > @@ -1688,6 +1688,21 @@
> > b43_poison_rx_buffer(ring, skb);
> > sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
> > }
> > +void b43_dma_rx_discard(struct b43_dmaring *ring)
> > +{
> > + B43_WARN_ON(ring->tx);
> > +
> > + /* Device has filled all buffers, drop all packets in buffers
> > + * and let TCP decrease speed.
> > + * Set index to one desc after the last one (which is marked)
> > + * so the device will see all slots as free again
> > + */
> > + /*
> > + *TODO: How to increase rx_drop in mac80211
> > + */
> > + b43_dma_write(ring, B43_DMA32_RXINDEX, ring->nr_slots *
> > + sizeof(struct b43_dmadesc32));
> > +}
> >
> > void b43_dma_rx(struct b43_dmaring *ring)
> > {
> >
> > Index: drivers/net/wireless/b43/dma.h
> > ===================================================================
> > --- compat-wireless-2012-09-07.orig/drivers/net/wireless/b43/dma.h
> > 2013-04-09 17:34:09.561397686 +0200
> > +++ compat-wireless-2012-09-07/drivers/net/wireless/b43/dma.h
> > 2013-04-09 17:34:43.461565780 +0200
> > @@ -10,7 +10,8 @@
> > #define B43_DMAIRQ_FATALMASK ((1 << 10) | (1 << 11) | (1 << 12) \
> > | (1 << 14) | (1 << 15))
> > #define B43_DMAIRQ_NONFATALMASK (1 << 13)
> > -#define B43_DMAIRQ_RX_DONE (1 << 16)
> > +#define B43_DMAIRQ_RX_DONE (1 << 16)
>
> Unnecessary whitespace change.
>
> > +#define B43_DMAIRQ_RDESC_UFLOW (1 << 13)
>
> Why not just rename B43_DMAIRQ_NONFATALMASK ?
>
> >
> > /*** 32-bit DMA Engine. ***/
> >
> > @@ -295,6 +296,8 @@
> > void b43_dma_handle_txstatus(struct b43_wldev *dev,
> > const struct b43_txstatus *status);
> >
> > +void b43_dma_rx_discard(struct b43_dmaring *ring);
> > +
> > void b43_dma_rx(struct b43_dmaring *ring);
> >
> > void b43_dma_direct_fifo_rx(struct b43_wldev *dev,
> >
> > Index: drivers/net/wireless/b43/main.c
> > ===================================================================
> > --- compat-wireless-2012-09-07.orig/drivers/net/wireless/b43/main.c
> > 2013-04-09 17:33:54.325322046 +0200
> > +++ compat-wireless-2012-09-07/drivers/net/wireless/b43/main.c
> > 2013-04-09 18:08:01.011471215 +0200
> > @@ -1894,14 +1894,6 @@
> > b43_controller_restart(dev, "DMA error");
> > return;
> > }
> > - if (merged_dma_reason & B43_DMAIRQ_NONFATALMASK) {
> > - b43err(dev->wl, "DMA error: "
> > - "0x%08X, 0x%08X, 0x%08X, "
> > - "0x%08X, 0x%08X, 0x%08X\n",
> > - dma_reason[0], dma_reason[1],
> > - dma_reason[2], dma_reason[3],
> > - dma_reason[4], dma_reason[5]);
> > - }
>
> You should say why you remove this one, and you should remove the
> B43_DMAIRQ_NONFATALMASK from the if (unlikely()) enclosing it.
>
> > }
> >
> > if (unlikely(reason & B43_IRQ_UCODE_DEBUG))
> > @@ -1920,6 +1912,14 @@
> > handle_irq_noise(dev);
> >
> > /* Check the DMA reason registers for received data. */
> > + if (dma_reason[0] & B43_DMAIRQ_RDESC_UFLOW) {
> > + //only print 256 time to not flood log
> > + if(!(dev->stats.rxdesc_underruns++&0xFF)){
> > + b43warn(dev->wl, "Rx descriptor underrun
> > (high cpu load?), throwing packets\n");
>
> Apart from the style problems, maybe doing a
> if (printk_ratelimit())
> b43warn(...);
>
> which will ensure that it won't flood the log, but still won't stop
> reporting them after the 256th time.
>
>
> > + }
> > + b43_dma_rx_discard(dev->dma.rx_ring);
> > +
> > + }
> > if (dma_reason[0] & B43_DMAIRQ_RX_DONE) {
> > if (b43_using_pio_transfers(dev))
> > b43_pio_rx(dev->pio.rx_queue);
> > @@ -1977,7 +1977,7 @@
> > return IRQ_NONE;
> >
> > dev->dma_reason[0] = b43_read32(dev, B43_MMIO_DMA0_REASON)
> > - & 0x0001DC00;
> > + & 0x0001FC00;
> > dev->dma_reason[1] = b43_read32(dev, B43_MMIO_DMA1_REASON)
> > & 0x0000DC00;
> > dev->dma_reason[2] = b43_read32(dev, B43_MMIO_DMA2_REASON)
> > @@ -3081,7 +3081,7 @@
> > b43_write32(dev, 0x018C, 0x02000000);
> > }
> > b43_write32(dev, B43_MMIO_GEN_IRQ_REASON, 0x00004000);
> > - b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001DC00);
> > + b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001FC00);
> > b43_write32(dev, B43_MMIO_DMA1_IRQ_MASK, 0x0000DC00);
> > b43_write32(dev, B43_MMIO_DMA2_IRQ_MASK, 0x0000DC00);
> > b43_write32(dev, B43_MMIO_DMA3_IRQ_MASK, 0x0001DC00);
> >
> > ===================================================================
> > --- compat-wireless-2012-09-07.orig/drivers/net/wireless/b43/b43.h
> > 2013-04-09 17:04:51.552680190 +0200
> > +++ compat-wireless-2012-09-07/drivers/net/wireless/b43/b43.h
> > 2013-04-09 17:46:08.472962612 +0200
> > @@ -671,6 +671,7 @@
> >
> > struct b43_stats {
> > u8 link_noise;
> > + u32 rxdesc_underruns;
> > };
> >
> > struct b43_key {
>
>
> Jonas
>
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