146 lines
5.2 KiB
Diff
146 lines
5.2 KiB
Diff
From 5921f167baf30255ebc079c6e751a7ed31cd986d Mon Sep 17 00:00:00 2001
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From: Thommy Jakobsson <thommyj@gmail.com>
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Date: Tue, 23 Apr 2013 21:45:11 +0200
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Subject: [PATCH 2/3] B43: Handle DMA RX descriptor underrun
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Add handling of rx descriptor underflow. This fixes a fault that could
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happen on slow machines, where data is received faster than the CPU can
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handle. In such a case the device will use up all rx descriptors and
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refuse to send any more data before confirming that it is ok. This
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patch enables necessary interrupt to discover such a situation and will
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handle them by dropping everything in the ring buffer.
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Reviewed-by: Michael Buesch <m@bues.ch>
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Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
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Cc: stable <stable@vger.kernel.org>
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---
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drivers/net/wireless/b43/dma.c | 19 +++++++++++++++++
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drivers/net/wireless/b43/dma.h | 4 +++-
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drivers/net/wireless/b43/main.c | 43 ++++++++++++++++-----------------------
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3 files changed, 40 insertions(+), 26 deletions(-)
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--- a/drivers/net/wireless/b43/dma.c
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+++ b/drivers/net/wireless/b43/dma.c
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@@ -1733,6 +1733,25 @@ drop_recycle_buffer:
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sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
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}
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+void b43_dma_handle_rx_overflow(struct b43_dmaring *ring)
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+{
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+ int current_slot, previous_slot;
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+
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+ B43_WARN_ON(ring->tx);
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+
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+ /* Device has filled all buffers, drop all packets and let TCP
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+ * decrease speed.
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+ * Decrement RX index by one will let the device to see all slots
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+ * as free again
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+ */
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+ /*
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+ *TODO: How to increase rx_drop in mac80211?
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+ */
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+ current_slot = ring->ops->get_current_rxslot(ring);
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+ previous_slot = prev_slot(ring, current_slot);
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+ ring->ops->set_current_rxslot(ring, previous_slot);
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+}
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+
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void b43_dma_rx(struct b43_dmaring *ring)
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{
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const struct b43_dma_ops *ops = ring->ops;
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--- a/drivers/net/wireless/b43/dma.h
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+++ b/drivers/net/wireless/b43/dma.h
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@@ -9,7 +9,7 @@
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/* DMA-Interrupt reasons. */
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#define B43_DMAIRQ_FATALMASK ((1 << 10) | (1 << 11) | (1 << 12) \
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| (1 << 14) | (1 << 15))
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-#define B43_DMAIRQ_NONFATALMASK (1 << 13)
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+#define B43_DMAIRQ_RDESC_UFLOW (1 << 13)
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#define B43_DMAIRQ_RX_DONE (1 << 16)
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/*** 32-bit DMA Engine. ***/
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@@ -295,6 +295,8 @@ int b43_dma_tx(struct b43_wldev *dev,
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void b43_dma_handle_txstatus(struct b43_wldev *dev,
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const struct b43_txstatus *status);
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+void b43_dma_handle_rx_overflow(struct b43_dmaring *ring);
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+
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void b43_dma_rx(struct b43_dmaring *ring);
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void b43_dma_direct_fifo_rx(struct b43_wldev *dev,
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--- a/drivers/net/wireless/b43/main.c
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+++ b/drivers/net/wireless/b43/main.c
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@@ -1907,32 +1907,20 @@ static void b43_do_interrupt_thread(stru
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}
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}
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- if (unlikely(merged_dma_reason & (B43_DMAIRQ_FATALMASK |
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- B43_DMAIRQ_NONFATALMASK))) {
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- if (merged_dma_reason & B43_DMAIRQ_FATALMASK) {
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- b43err(dev->wl, "Fatal DMA error: "
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- "0x%08X, 0x%08X, 0x%08X, "
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- "0x%08X, 0x%08X, 0x%08X\n",
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- dma_reason[0], dma_reason[1],
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- dma_reason[2], dma_reason[3],
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- dma_reason[4], dma_reason[5]);
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+ if (unlikely(merged_dma_reason & (B43_DMAIRQ_FATALMASK))) {
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+ b43err(dev->wl,
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+ "Fatal DMA error: 0x%08X, 0x%08X, 0x%08X, 0x%08X, 0x%08X, 0x%08X\n",
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+ dma_reason[0], dma_reason[1],
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+ dma_reason[2], dma_reason[3],
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+ dma_reason[4], dma_reason[5]);
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#ifdef CONFIG_B43_PIO
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- b43err(dev->wl, "This device does not support DMA "
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+ b43err(dev->wl, "This device does not support DMA "
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"on your system. It will now be switched to PIO.\n");
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- /* Fall back to PIO transfers if we get fatal DMA errors! */
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- dev->use_pio = true;
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+ /* Fall back to PIO transfers if we get fatal DMA errors! */
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+ dev->use_pio = true;
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#endif
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- b43_controller_restart(dev, "DMA error");
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- return;
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- }
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- if (merged_dma_reason & B43_DMAIRQ_NONFATALMASK) {
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- b43err(dev->wl, "DMA error: "
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- "0x%08X, 0x%08X, 0x%08X, "
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- "0x%08X, 0x%08X, 0x%08X\n",
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- dma_reason[0], dma_reason[1],
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- dma_reason[2], dma_reason[3],
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- dma_reason[4], dma_reason[5]);
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- }
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+ b43_controller_restart(dev, "DMA error");
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+ return;
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}
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if (unlikely(reason & B43_IRQ_UCODE_DEBUG))
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@@ -1951,6 +1939,11 @@ static void b43_do_interrupt_thread(stru
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handle_irq_noise(dev);
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/* Check the DMA reason registers for received data. */
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+ if (dma_reason[0] & B43_DMAIRQ_RDESC_UFLOW) {
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+ if (B43_DEBUG)
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+ b43warn(dev->wl, "RX descriptor underrun\n");
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+ b43_dma_handle_rx_overflow(dev->dma.rx_ring);
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+ }
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if (dma_reason[0] & B43_DMAIRQ_RX_DONE) {
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if (b43_using_pio_transfers(dev))
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b43_pio_rx(dev->pio.rx_queue);
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@@ -2008,7 +2001,7 @@ static irqreturn_t b43_do_interrupt(stru
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return IRQ_NONE;
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dev->dma_reason[0] = b43_read32(dev, B43_MMIO_DMA0_REASON)
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- & 0x0001DC00;
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+ & 0x0001FC00;
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dev->dma_reason[1] = b43_read32(dev, B43_MMIO_DMA1_REASON)
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& 0x0000DC00;
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dev->dma_reason[2] = b43_read32(dev, B43_MMIO_DMA2_REASON)
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@@ -3137,7 +3130,7 @@ static int b43_chip_init(struct b43_wlde
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b43_write32(dev, 0x018C, 0x02000000);
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}
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b43_write32(dev, B43_MMIO_GEN_IRQ_REASON, 0x00004000);
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- b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001DC00);
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+ b43_write32(dev, B43_MMIO_DMA0_IRQ_MASK, 0x0001FC00);
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b43_write32(dev, B43_MMIO_DMA1_IRQ_MASK, 0x0000DC00);
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b43_write32(dev, B43_MMIO_DMA2_IRQ_MASK, 0x0000DC00);
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b43_write32(dev, B43_MMIO_DMA3_IRQ_MASK, 0x0001DC00);
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