Linux wireless drivers development
 help / color / mirror / Atom feed
* [PATCH] rt2800pci: fix spurious interrupts generation
@ 2012-01-13 11:59 Stanislaw Gruszka
  2012-01-13 12:19 ` Helmut Schaa
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Stanislaw Gruszka @ 2012-01-13 11:59 UTC (permalink / raw)
  To: John W. Linville
  Cc: Amir Hedayaty, Ivo van Doorn, Gertjan van Wingerde, Helmut Schaa,
	linux-wireless

Same devices can generate interrupt without properly setting bit in
INT_SOURCE_CSR register (spurious interrupt), what will cause IRQ line
will be disabled by interrupts controller driver.

We discovered that clearing INT_MASK_CSR stops such behaviour. We
previously first read that register, and then clear all know interrupt
sources bits and do not touch reserved bits. After this patch, we write
to all register content (I believe writing to reserved bits on that
register will not cause any problems, I tested that on my rt2800pci
device).

This fix very bad performance problem, practically making device
unusable (since worked without interrupts), reported in:
https://bugzilla.redhat.com/show_bug.cgi?id=658451

We previously tried to workaround that issue in commit
4ba7d9997869d25bd223dea7536fc1ce9fab3b3b "rt2800pci: handle spurious
interrupts", but it was reverted in commit
82e5fc2a34fa9ffea38f00c4066b7e600a0ca5e6
as thing, that will prevent to detect real spurious interrupts.

Reported-and-tested-by: Amir Hedayaty <hedayaty@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/rt2x00/rt2800pci.c |   28 ++++++++--------------------
 1 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index 4941a1a..dc88bae 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -422,7 +422,6 @@ static int rt2800pci_init_queues(struct rt2x00_dev *rt2x00dev)
 static void rt2800pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
 				 enum dev_state state)
 {
-	int mask = (state == STATE_RADIO_IRQ_ON);
 	u32 reg;
 	unsigned long flags;
 
@@ -436,25 +435,14 @@ static void rt2800pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
 	}
 
 	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
-	rt2x00pci_register_read(rt2x00dev, INT_MASK_CSR, &reg);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_RXDELAYINT, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_TXDELAYINT, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_RX_DONE, mask);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_AC0_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_AC1_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_AC2_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_AC3_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_HCCA_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_MGMT_DMA_DONE, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_MCU_COMMAND, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_RXTX_COHERENT, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_TBTT, mask);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_PRE_TBTT, mask);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_TX_FIFO_STATUS, mask);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_AUTO_WAKEUP, mask);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_GPTIMER, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_RX_COHERENT, 0);
-	rt2x00_set_field32(&reg, INT_MASK_CSR_TX_COHERENT, 0);
+	reg = 0;
+	if (state == STATE_RADIO_IRQ_ON) {
+		rt2x00_set_field32(&reg, INT_MASK_CSR_RX_DONE, 1);
+		rt2x00_set_field32(&reg, INT_MASK_CSR_TBTT, 1);
+		rt2x00_set_field32(&reg, INT_MASK_CSR_PRE_TBTT, 1);
+		rt2x00_set_field32(&reg, INT_MASK_CSR_TX_FIFO_STATUS, 1);
+		rt2x00_set_field32(&reg, INT_MASK_CSR_AUTO_WAKEUP, 1);
+	}
 	rt2x00pci_register_write(rt2x00dev, INT_MASK_CSR, reg);
 	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
 
-- 
1.7.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2012-01-15  9:20 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-01-13 11:59 [PATCH] rt2800pci: fix spurious interrupts generation Stanislaw Gruszka
2012-01-13 12:19 ` Helmut Schaa
2012-01-13 17:47 ` Gertjan van Wingerde
2012-01-15  9:20 ` Ivo Van Doorn

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox