From ada8d4a5e2ed9de8a5a58788c4b6a4c8103e0f8d Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Fri, 14 May 2010 12:05:25 -0700 Subject: [PATCH] OMAP2/3/4: DMA: disable channel interrupts in omap_init_dma() If we are softbooting another kernel using kexec, DMA controller state is not known when we are performing omap_init_dma(). It is possible that some DMA channels are already active. For example after kexec we get: <4>IRQ 0020 for non-allocated DMAchannel 5 <4>IRQ 0020 for non-allocated DMAchannel 5 <4>IRQ 0020 for non-allocated DMAchannel 5 <4>IRQ 0020 for non-allocated DMAchannel 5 <4>IRQ 0020 for non-allocated DMAchannel 5 To prevent any weird things happening, we disable all channel interrupts during init. Signed-off-by: Mika Westerberg Acked-by: Kevin Hilman Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/dma.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 1d959965ff52..ad42ec3592e5 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -709,6 +709,21 @@ static inline void omap2_enable_irq_lch(int lch) spin_unlock_irqrestore(&dma_chan_lock, flags); } +static inline void omap2_disable_irq_lch(int lch) +{ + u32 val; + unsigned long flags; + + if (!cpu_class_is_omap2()) + return; + + spin_lock_irqsave(&dma_chan_lock, flags); + val = dma_read(IRQENABLE_L0); + val &= ~(1 << lch); + dma_write(val, IRQENABLE_L0); + spin_unlock_irqrestore(&dma_chan_lock, flags); +} + int omap_request_dma(int dev_id, const char *dev_name, void (*callback)(int lch, u16 ch_status, void *data), void *data, int *dma_ch_out) @@ -807,14 +822,7 @@ void omap_free_dma(int lch) } if (cpu_class_is_omap2()) { - u32 val; - - spin_lock_irqsave(&dma_chan_lock, flags); - /* Disable interrupts */ - val = dma_read(IRQENABLE_L0); - val &= ~(1 << lch); - dma_write(val, IRQENABLE_L0); - spin_unlock_irqrestore(&dma_chan_lock, flags); + omap2_disable_irq_lch(lch); /* Clear the CSR register and IRQ status register */ dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR(lch)); @@ -2107,6 +2115,9 @@ static int __init omap_init_dma(void) for (ch = 0; ch < dma_chan_count; ch++) { omap_clear_dma(ch); + if (cpu_class_is_omap2()) + omap2_disable_irq_lch(ch); + dma_chan[ch].dev_id = -1; dma_chan[ch].next_lch = -1; -- 2.39.5