113 lines
4.2 KiB
Diff
113 lines
4.2 KiB
Diff
From: Quintin Pitts <geek4linux@gmail.com>
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Date: Fri, 9 Apr 2010 21:37:38 +0200
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Subject: [PATCH] p54pci: prevent stuck rx-ring on slow system
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commit 5988f385b4cffa9ca72c5be0188e5f4c9ef46d82 upstream.
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This patch fixes an old problem, which - under certain
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circumstances - could cause the device to become
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unresponsive.
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most of p54pci's rx-ring management is implemented in just
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two distinct standalone functions. p54p_check_rx_ring takes
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care of processing incoming data, while p54p_refill_rx_ring
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tries to replenish all depleted communication buffers.
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This has always worked fine on my fast machine, but
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now I know there is a hidden race...
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The most likely candidate here is ring_control->device_idx.
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Quintin Pitts had already analyzed the culprit and posted
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a patch back in Oct 2009. But sadly, no one's picked up on this.
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( https://patchwork.kernel.org/patch/53079/ [2 & 3] ).
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This patch does the same way, except that it also prioritize
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rx data processing, simply because tx routines *can* wait.
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Reported-by: Sean Young <sean@mess.org>
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Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=11386
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Reported-by: Quintin Pitts <geek4linux@gmail.com>
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Signed-off-by: Quintin Pitts <geek4linux@gmail.com>
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Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
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Signed-off-by: John W. Linville <linville@tuxdriver.com>
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---
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drivers/net/wireless/p54/p54pci.c | 26 +++++++++++++-------------
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1 files changed, 13 insertions(+), 13 deletions(-)
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diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
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index ed4bdff..aa29663 100644
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--- a/drivers/net/wireless/p54/p54pci.c
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+++ b/drivers/net/wireless/p54/p54pci.c
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@@ -131,7 +131,7 @@ static int p54p_upload_firmware(struct ieee80211_hw *dev)
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static void p54p_refill_rx_ring(struct ieee80211_hw *dev,
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int ring_index, struct p54p_desc *ring, u32 ring_limit,
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- struct sk_buff **rx_buf)
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+ struct sk_buff **rx_buf, u32 index)
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{
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struct p54p_priv *priv = dev->priv;
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struct p54p_ring_control *ring_control = priv->ring_control;
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@@ -139,7 +139,7 @@ static void p54p_refill_rx_ring(struct ieee80211_hw *dev,
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idx = le32_to_cpu(ring_control->host_idx[ring_index]);
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limit = idx;
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- limit -= le32_to_cpu(ring_control->device_idx[ring_index]);
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+ limit -= le32_to_cpu(index);
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limit = ring_limit - limit;
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i = idx % ring_limit;
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@@ -231,7 +231,7 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
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i %= ring_limit;
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}
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- p54p_refill_rx_ring(dev, ring_index, ring, ring_limit, rx_buf);
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+ p54p_refill_rx_ring(dev, ring_index, ring, ring_limit, rx_buf, *index);
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}
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static void p54p_check_tx_ring(struct ieee80211_hw *dev, u32 *index,
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@@ -276,14 +276,6 @@ static void p54p_tasklet(unsigned long dev_id)
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struct p54p_priv *priv = dev->priv;
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struct p54p_ring_control *ring_control = priv->ring_control;
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- p54p_check_tx_ring(dev, &priv->tx_idx_mgmt, 3, ring_control->tx_mgmt,
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- ARRAY_SIZE(ring_control->tx_mgmt),
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- priv->tx_buf_mgmt);
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-
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- p54p_check_tx_ring(dev, &priv->tx_idx_data, 1, ring_control->tx_data,
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- ARRAY_SIZE(ring_control->tx_data),
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- priv->tx_buf_data);
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-
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p54p_check_rx_ring(dev, &priv->rx_idx_mgmt, 2, ring_control->rx_mgmt,
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ARRAY_SIZE(ring_control->rx_mgmt), priv->rx_buf_mgmt);
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@@ -292,6 +284,14 @@ static void p54p_tasklet(unsigned long dev_id)
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wmb();
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P54P_WRITE(dev_int, cpu_to_le32(ISL38XX_DEV_INT_UPDATE));
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+
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+ p54p_check_tx_ring(dev, &priv->tx_idx_mgmt, 3, ring_control->tx_mgmt,
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+ ARRAY_SIZE(ring_control->tx_mgmt),
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+ priv->tx_buf_mgmt);
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+
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+ p54p_check_tx_ring(dev, &priv->tx_idx_data, 1, ring_control->tx_data,
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+ ARRAY_SIZE(ring_control->tx_data),
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+ priv->tx_buf_data);
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}
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static irqreturn_t p54p_interrupt(int irq, void *dev_id)
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@@ -444,10 +444,10 @@ static int p54p_open(struct ieee80211_hw *dev)
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priv->rx_idx_mgmt = priv->tx_idx_mgmt = 0;
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p54p_refill_rx_ring(dev, 0, priv->ring_control->rx_data,
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- ARRAY_SIZE(priv->ring_control->rx_data), priv->rx_buf_data);
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+ ARRAY_SIZE(priv->ring_control->rx_data), priv->rx_buf_data, 0);
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p54p_refill_rx_ring(dev, 2, priv->ring_control->rx_mgmt,
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- ARRAY_SIZE(priv->ring_control->rx_mgmt), priv->rx_buf_mgmt);
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+ ARRAY_SIZE(priv->ring_control->rx_mgmt), priv->rx_buf_mgmt, 0);
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P54P_WRITE(ring_control_base, cpu_to_le32(priv->ring_control_dma));
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P54P_READ(ring_control_base);
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--
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1.7.1
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