From 8ccefda4fc93ef2ba2cc177644755a0460d07710 Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Fri, 13 Jan 2012 12:59:32 +0100 Subject: [PATCH] rt2800pci: fix spurious interrupts generation 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 bd01c4c5cb98abf93a4ba39144c9f130153f96f5 "rt2800pci: handle spurious interrupts", but it was reverted in commit facdf6759680984864da57d6d5b5d150720d39bf as thing, that will prevent to detect real spurious interrupts. Reported-and-tested-by: Amir Hedayaty Cc: stable@vger.kernel.org Signed-off-by: Stanislaw Gruszka Acked-by: Gertjan van Wingerde Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt2800pci.c | 28 +++++++------------------ 1 file changed, 8 insertions(+), 20 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c index 4941a1a232190..dc88baefa72e8 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, ®); - rt2x00_set_field32(®, INT_MASK_CSR_RXDELAYINT, 0); - rt2x00_set_field32(®, INT_MASK_CSR_TXDELAYINT, 0); - rt2x00_set_field32(®, INT_MASK_CSR_RX_DONE, mask); - rt2x00_set_field32(®, INT_MASK_CSR_AC0_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_AC1_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_AC2_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_AC3_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_HCCA_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_MGMT_DMA_DONE, 0); - rt2x00_set_field32(®, INT_MASK_CSR_MCU_COMMAND, 0); - rt2x00_set_field32(®, INT_MASK_CSR_RXTX_COHERENT, 0); - rt2x00_set_field32(®, INT_MASK_CSR_TBTT, mask); - rt2x00_set_field32(®, INT_MASK_CSR_PRE_TBTT, mask); - rt2x00_set_field32(®, INT_MASK_CSR_TX_FIFO_STATUS, mask); - rt2x00_set_field32(®, INT_MASK_CSR_AUTO_WAKEUP, mask); - rt2x00_set_field32(®, INT_MASK_CSR_GPTIMER, 0); - rt2x00_set_field32(®, INT_MASK_CSR_RX_COHERENT, 0); - rt2x00_set_field32(®, INT_MASK_CSR_TX_COHERENT, 0); + reg = 0; + if (state == STATE_RADIO_IRQ_ON) { + rt2x00_set_field32(®, INT_MASK_CSR_RX_DONE, 1); + rt2x00_set_field32(®, INT_MASK_CSR_TBTT, 1); + rt2x00_set_field32(®, INT_MASK_CSR_PRE_TBTT, 1); + rt2x00_set_field32(®, INT_MASK_CSR_TX_FIFO_STATUS, 1); + rt2x00_set_field32(®, INT_MASK_CSR_AUTO_WAKEUP, 1); + } rt2x00pci_register_write(rt2x00dev, INT_MASK_CSR, reg); spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags); -- 2.39.5