From 9848d38aedf18842322974a43140ccf1bfd09347 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 24 Apr 2010 17:24:11 +0000 Subject: [PATCH] ar71xx: fix a wifi card stability issue when we receive a pci/ahb interrupt, we need to flush pending data for dma from the device, otherwise the tx path may get stuck if the completion flag of the dma descriptor is not updated at the time the tx interrupt arrives. SVN-Revision: 21143 --- .../linux/ar71xx/files/arch/mips/ar71xx/irq.c | 27 ++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/target/linux/ar71xx/files/arch/mips/ar71xx/irq.c b/target/linux/ar71xx/files/arch/mips/ar71xx/irq.c index eecdd9f714..4e1da167dd 100644 --- a/target/linux/ar71xx/files/arch/mips/ar71xx/irq.c +++ b/target/linux/ar71xx/files/arch/mips/ar71xx/irq.c @@ -21,6 +21,8 @@ #include +static int ip2_flush_reg; + static void ar71xx_gpio_irq_dispatch(void) { void __iomem *base = ar71xx_gpio_base; @@ -239,8 +241,17 @@ asmlinkage void plat_irq_dispatch(void) if (pending & STATUSF_IP7) do_IRQ(AR71XX_CPU_IRQ_TIMER); - else if (pending & STATUSF_IP2) + else if (pending & STATUSF_IP2) { + /* + * This IRQ is meant for a PCI device. Drivers for PCI devices + * typically allocate coherent DMA memory for the descriptor + * ring, however the DMA controller may still have some + * unsynchronized data in the FIFO. + * Issue a flush here to ensure that the driver sees the update. + */ + ar71xx_ddr_flush(ip2_flush_reg); do_IRQ(AR71XX_CPU_IRQ_IP2); + } else if (pending & STATUSF_IP4) do_IRQ(AR71XX_CPU_IRQ_GE0); @@ -260,6 +271,20 @@ asmlinkage void plat_irq_dispatch(void) void __init arch_init_irq(void) { + switch(ar71xx_soc) { + case AR71XX_SOC_AR7240: + case AR71XX_SOC_AR7241: + case AR71XX_SOC_AR7242: + ip2_flush_reg = AR724X_DDR_REG_FLUSH_PCIE; + break; + case AR71XX_SOC_AR9130: + case AR71XX_SOC_AR9132: + ip2_flush_reg = AR91XX_DDR_REG_FLUSH_WMAC; + break; + default: + ip2_flush_reg = AR71XX_DDR_REG_FLUSH_PCI; + break; + } mips_cpu_irq_init(); ar71xx_misc_irq_init(); -- 2.30.2