+++ /dev/null
-From 5921f167baf30255ebc079c6e751a7ed31cd986d Mon Sep 17 00:00:00 2001
-From: Thommy Jakobsson <thommyj@gmail.com>
-Date: Tue, 23 Apr 2013 21:45:11 +0200
-Subject: [PATCH 2/3] B43: Handle DMA RX descriptor underrun
-
-Add handling of rx descriptor underflow. This fixes a fault that could
-happen on slow machines, where data is received faster than the CPU can
-handle. In such a case the device will use up all rx descriptors and
-refuse to send any more data before confirming that it is ok. This
-patch enables necessary interrupt to discover such a situation and will
-handle them by dropping everything in the ring buffer.
-
-Reviewed-by: Michael Buesch <m@bues.ch>
-Signed-off-by: Thommy Jakobsson <thommyj@gmail.com>
-Cc: stable <stable@vger.kernel.org>
----
- drivers/net/wireless/b43/dma.c | 19 +++++++++++++++++
- drivers/net/wireless/b43/dma.h | 4 +++-
- drivers/net/wireless/b43/main.c | 43 ++++++++++++++++-----------------------
- 3 files changed, 40 insertions(+), 26 deletions(-)
-
---- a/drivers/net/wireless/b43/dma.c
-+++ b/drivers/net/wireless/b43/dma.c
-@@ -1733,6 +1733,25 @@ drop_recycle_buffer:
- sync_descbuffer_for_device(ring, dmaaddr, ring->rx_buffersize);
- }
-
-+void b43_dma_handle_rx_overflow(struct b43_dmaring *ring)
-+{
-+ int current_slot, previous_slot;
-+
-+ B43_WARN_ON(ring->tx);
-+
-+ /* Device has filled all buffers, drop all packets and let TCP
-+ * decrease speed.
-+ * Decrement RX index by one will let the device to see all slots
-+ * as free again
-+ */
-+ /*
-+ *TODO: How to increase rx_drop in mac80211?
-+ */
-+ current_slot = ring->ops->get_current_rxslot(ring);
-+ previous_slot = prev_slot(ring, current_slot);
-+ ring->ops->set_current_rxslot(ring, previous_slot);
-+}
-+
- void b43_dma_rx(struct b43_dmaring *ring)
- {
- const struct b43_dma_ops *ops = ring->ops;
---- 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_handle_rx_overflow(struct b43_dmaring *ring);
-+
- void b43_dma_rx(struct b43_dmaring *ring);
-
- void b43_dma_direct_fifo_rx(struct b43_wldev *dev,
---- a/drivers/net/wireless/b43/main.c
-+++ b/drivers/net/wireless/b43/main.c
-@@ -1907,32 +1907,20 @@ static void b43_do_interrupt_thread(stru
- }
- }
-
-- 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]);
-+ 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]);
- #ifdef CONFIG_B43_PIO
-- b43err(dev->wl, "This device does not support DMA "
-+ 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;
-+ /* Fall back to PIO transfers if we get fatal DMA errors! */
-+ dev->use_pio = true;
- #endif
-- 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]);
-- }
-+ b43_controller_restart(dev, "DMA error");
-+ return;
- }
-
- if (unlikely(reason & B43_IRQ_UCODE_DEBUG))
-@@ -1951,6 +1939,11 @@ static void b43_do_interrupt_thread(stru
- handle_irq_noise(dev);
-
- /* Check the DMA reason registers for received data. */
-+ if (dma_reason[0] & B43_DMAIRQ_RDESC_UFLOW) {
-+ if (B43_DEBUG)
-+ b43warn(dev->wl, "RX descriptor underrun\n");
-+ b43_dma_handle_rx_overflow(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);
-@@ -2008,7 +2001,7 @@ static irqreturn_t b43_do_interrupt(stru
- 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)
-@@ -3137,7 +3130,7 @@ static int b43_chip_init(struct b43_wlde
- 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);
projects / openwrt / openwrt.git / blobdiff