diff options
| author | Quintin Pitts <geek4linux@gmail.com> | 2010-04-09 21:37:38 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2010-04-12 15:22:10 -0400 |
| commit | 5988f385b4cffa9ca72c5be0188e5f4c9ef46d82 (patch) | |
| tree | 2c79481788945047c97b4ffe54a3c49362c3789a | |
| parent | b1f90866fb3a329b1c4ebfff93ae9c110943e50a (diff) | |
p54pci: prevent stuck rx-ring on slow system
This patch fixes an old problem, which - under certain
circumstances - could cause the device to become
unresponsive.
most of p54pci's rx-ring management is implemented in just
two distinct standalone functions. p54p_check_rx_ring takes
care of processing incoming data, while p54p_refill_rx_ring
tries to replenish all depleted communication buffers.
This has always worked fine on my fast machine, but
now I know there is a hidden race...
The most likely candidate here is ring_control->device_idx.
Quintin Pitts had already analyzed the culprit and posted
a patch back in Oct 2009. But sadly, no one's picked up on this.
( https://patchwork.kernel.org/patch/53079/ [2 & 3] ).
This patch does the same way, except that it also prioritize
rx data processing, simply because tx routines *can* wait.
Reported-by: Sean Young <sean@mess.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=11386
Reported-by: Quintin Pitts <geek4linux@gmail.com>
Signed-off-by: Quintin Pitts <geek4linux@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/p54/p54pci.c | 26 |
1 files changed, 13 insertions, 13 deletions
diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c index ed4bdffdd63..aa29663bf6c 100644 --- a/drivers/net/wireless/p54/p54pci.c +++ b/drivers/net/wireless/p54/p54pci.c @@ -131,7 +131,7 @@ static int p54p_upload_firmware(struct ieee80211_hw *dev) static void p54p_refill_rx_ring(struct ieee80211_hw *dev, int ring_index, struct p54p_desc *ring, u32 ring_limit, - struct sk_buff **rx_buf) + struct sk_buff **rx_buf, u32 index) { struct p54p_priv *priv = dev->priv; struct p54p_ring_control *ring_control = priv->ring_control; @@ -139,7 +139,7 @@ static void p54p_refill_rx_ring(struct ieee80211_hw *dev, idx = le32_to_cpu(ring_control->host_idx[ring_index]); limit = idx; - limit -= le32_to_cpu(ring_control->device_idx[ring_index]); + limit -= le32_to_cpu(index); limit = ring_limit - limit; i = idx % ring_limit; @@ -231,7 +231,7 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index, i %= ring_limit; } - p54p_refill_rx_ring(dev, ring_index, ring, ring_limit, rx_buf); + p54p_refill_rx_ring(dev, ring_index, ring, ring_limit, rx_buf, *index); } static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index, @@ -276,14 +276,6 @@ static void p54p_tasklet(unsigned long dev_id) struct p54p_priv *priv = dev->priv; struct p54p_ring_control *ring_control = priv->ring_control; - p54p_check_tx_ring(dev, &priv->tx_idx_mgmt, 3, ring_control->tx_mgmt, - ARRAY_SIZE(ring_control->tx_mgmt), - priv->tx_buf_mgmt); - - p54p_check_tx_ring(dev, &priv->tx_idx_data, 1, ring_control->tx_data, - ARRAY_SIZE(ring_control->tx_data), - priv->tx_buf_data); - p54p_check_rx_ring(dev, &priv->rx_idx_mgmt, 2, ring_control->rx_mgmt, ARRAY_SIZE(ring_control->rx_mgmt), priv->rx_buf_mgmt); @@ -292,6 +284,14 @@ static void p54p_tasklet(unsigned long dev_id) wmb(); P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_UPDATE)); + + p54p_check_tx_ring(dev, &priv->tx_idx_mgmt, 3, ring_control->tx_mgmt, + ARRAY_SIZE(ring_control->tx_mgmt), + priv->tx_buf_mgmt); + + p54p_check_tx_ring(dev, &priv->tx_idx_data, 1, ring_control->tx_data, + ARRAY_SIZE(ring_control->tx_data), + priv->tx_buf_data); } static irqreturn_t p54p_interrupt(int irq, void *dev_id) @@ -444,10 +444,10 @@ static int p54p_open(struct ieee80211_hw *dev) priv->rx_idx_mgmt = priv->tx_idx_mgmt = 0; p54p_refill_rx_ring(dev, 0, priv->ring_control->rx_data, - ARRAY_SIZE(priv->ring_control->rx_data), priv->rx_buf_data); + ARRAY_SIZE(priv->ring_control->rx_data), priv->rx_buf_data, 0); p54p_refill_rx_ring(dev, 2, priv->ring_control->rx_mgmt, - ARRAY_SIZE(priv->ring_control->rx_mgmt), priv->rx_buf_mgmt); + ARRAY_SIZE(priv->ring_control->rx_mgmt), priv->rx_buf_mgmt, 0); P54P_WRITE(ring_control_base, cpu_to_le32(priv->ring_control_dma)); P54P_READ(ring_control_base); |