mac80211: rt2x00: add support for the RT3662/RT3883 SoCs

[openwrt.git] / package / kernel / mac80211 / patches / 600-0034-rt2x00-rt2800mmio-add-a-workaround-for-spurious-TX_F.patch

diff --git a/package/kernel/mac80211/patches/600-0034-rt2x00-rt2800mmio-add-a-workaround-for-spurious-TX_F.patch b/package/kernel/mac80211/patches/600-0034-rt2x00-rt2800mmio-add-a-workaround-for-spurious-TX_F.patch
new file mode 100644 (file)
index 0000000..79334dd
--- /dev/null
+++ b/package/kernel/mac80211/patches/600-0034-rt2x00-rt2800mmio-add-a-workaround-for-spurious-TX_F.patch
@@ -0,0 +1,136 @@
+From 5e67d4f8a46d19748b501c2ef86de3f50d3cfd51 Mon Sep 17 00:00:00 2001
+From: Gabor Juhos <juhosg@openwrt.org>
+Date: Sun, 24 Mar 2013 19:26:27 +0100
+Subject: [PATCH] rt2x00: rt2800mmio: add a workaround for spurious
+ TX_FIFO_STATUS interrupts
+
+Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
+---
+ drivers/net/wireless/rt2x00/rt2800mmio.c |   72 +++++++++++++++++++++++++-----
+ drivers/net/wireless/rt2x00/rt2x00.h     |    5 +++
+ 2 files changed, 65 insertions(+), 12 deletions(-)
+
+--- a/drivers/net/wireless/rt2x00/rt2800mmio.c
++++ b/drivers/net/wireless/rt2x00/rt2800mmio.c
+@@ -415,9 +415,9 @@ void rt2800mmio_autowake_tasklet(unsigne
+ }
+ EXPORT_SYMBOL_GPL(rt2800mmio_autowake_tasklet);
+ 
+-static void rt2800mmio_txstatus_interrupt(struct rt2x00_dev *rt2x00dev)
++static void rt2800mmio_txstatus_interrupt(struct rt2x00_dev *rt2x00dev,
++                                        u32 status)
+ {
+-      u32 status;
+       int i;
+ 
+       /*
+@@ -438,29 +438,77 @@ static void rt2800mmio_txstatus_interrup
+        * Since we have only one producer and one consumer we don't
+        * need to lock the kfifo.
+        */
+-      for (i = 0; i < rt2x00dev->tx->limit; i++) {
+-              rt2x00mmio_register_read(rt2x00dev, TX_STA_FIFO, &status);
+-
+-              if (!rt2x00_get_field32(status, TX_STA_FIFO_VALID))
+-                      break;
+-
++      i = 0;
++      do {
+               if (!kfifo_put(&rt2x00dev->txstatus_fifo, status)) {
+-                      rt2x00_warn(rt2x00dev, "TX status FIFO overrun, drop tx status report\n");
++                      rt2x00_warn(rt2x00dev,
++                                  "TX status FIFO overrun, drop TX status report\n");
+                       break;
+               }
+-      }
++
++              if (++i >= rt2x00dev->tx->limit)
++                      break;
++
++              rt2x00mmio_register_read(rt2x00dev, TX_STA_FIFO, &status);
++      } while (rt2x00_get_field32(status, TX_STA_FIFO_VALID));
+ 
+       /* Schedule the tasklet for processing the tx status. */
+       tasklet_schedule(&rt2x00dev->txstatus_tasklet);
+ }
+ 
++#define RT2800MMIO_TXSTATUS_IRQ_MAX_RETRIES   4
++
++static bool rt2800mmio_txstatus_is_spurious(struct rt2x00_dev *rt2x00dev,
++                                         u32 txstatus)
++{
++      if (likely(rt2x00_get_field32(txstatus, TX_STA_FIFO_VALID))) {
++              rt2x00dev->txstatus_irq_retries = 0;
++              return false;
++      }
++
++      rt2x00dev->txstatus_irq_retries++;
++
++      /* Ensure that we don't go into an infinite IRQ loop. */
++      if (rt2x00dev->txstatus_irq_retries >=
++          RT2800MMIO_TXSTATUS_IRQ_MAX_RETRIES) {
++              rt2x00_warn(rt2x00dev,
++                          "%u spurious TX_FIFO_STATUS interrupt(s)\n",
++                          rt2x00dev->txstatus_irq_retries);
++              rt2x00dev->txstatus_irq_retries = 0;
++              return false;
++      }
++
++      return true;
++}
++
+ irqreturn_t rt2800mmio_interrupt(int irq, void *dev_instance)
+ {
+       struct rt2x00_dev *rt2x00dev = dev_instance;
+       u32 reg, mask;
++      u32 txstatus = 0;
+ 
+-      /* Read status and ACK all interrupts */
++      /* Read status */
+       rt2x00mmio_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);
++
++      if (rt2x00_get_field32(reg, INT_SOURCE_CSR_TX_FIFO_STATUS)) {
++              /* Due to unknown reason the hardware generates a
++               * TX_FIFO_STATUS interrupt before the TX_STA_FIFO
++               * register contain valid data. Read the TX status
++               * here to see if we have to process the actual
++               * request.
++               */
++              rt2x00mmio_register_read(rt2x00dev, TX_STA_FIFO, &txstatus);
++              if (rt2800mmio_txstatus_is_spurious(rt2x00dev, txstatus)) {
++                      /* Remove the TX_FIFO_STATUS bit so it won't be
++                       * processed in this turn. The hardware will
++                       * generate another IRQ for us.
++                       */
++                      rt2x00_set_field32(&reg,
++                                         INT_SOURCE_CSR_TX_FIFO_STATUS, 0);
++              }
++      }
++
++      /* ACK interrupts */
+       rt2x00mmio_register_write(rt2x00dev, INT_SOURCE_CSR, reg);
+ 
+       if (!reg)
+@@ -477,7 +525,7 @@ irqreturn_t rt2800mmio_interrupt(int irq
+       mask = ~reg;
+ 
+       if (rt2x00_get_field32(reg, INT_SOURCE_CSR_TX_FIFO_STATUS)) {
+-              rt2800mmio_txstatus_interrupt(rt2x00dev);
++              rt2800mmio_txstatus_interrupt(rt2x00dev, txstatus);
+               /*
+                * Never disable the TX_FIFO_STATUS interrupt.
+                */
+--- a/drivers/net/wireless/rt2x00/rt2x00.h
++++ b/drivers/net/wireless/rt2x00/rt2x00.h
+@@ -986,6 +986,11 @@ struct rt2x00_dev {
+       int rf_channel;
+ 
+       /*
++       * Counter for tx status irq retries (rt2800pci).
++       */
++      unsigned int txstatus_irq_retries;
++
++      /*
+        * Protect the interrupt mask register.
+        */
+       spinlock_t irqmask_lock;