From fa3e686a34f4c33de31a128cc36def0b466bfe1a Mon Sep 17 00:00:00 2001 From: Pavel Pisa Date: Thu, 22 Jun 2006 22:21:03 +0100 Subject: [ARM] 3601/1: i.MX/MX1 DMA error handling for signaled channels only Patch from Pavel Pisa There has been bug, that dma_err_handler() touches even channels not signaling error condition. Problem noticed by Andrea Paterniani. Signed-off-by: Pavel Pisa Signed-off-by: Russell King --- arch/arm/mach-imx/dma.c | 65 +++++++++++++++++++++++++++++-------------------- 1 file changed, 39 insertions(+), 26 deletions(-) (limited to 'arch/arm') diff --git a/arch/arm/mach-imx/dma.c b/arch/arm/mach-imx/dma.c index 4ca51dcf13ac..36578871ecc8 100644 --- a/arch/arm/mach-imx/dma.c +++ b/arch/arm/mach-imx/dma.c @@ -15,6 +15,9 @@ * Changed to support scatter gather DMA * by taking Russell's code from RiscPC * + * 2006-05-31 Pavel Pisa + * Corrected error handling code. + * */ #undef DEBUG @@ -277,7 +280,7 @@ imx_dma_setup_sg(imx_dmach_t dma_ch, int imx_dma_setup_handlers(imx_dmach_t dma_ch, void (*irq_handler) (int, void *, struct pt_regs *), - void (*err_handler) (int, void *, struct pt_regs *), + void (*err_handler) (int, void *, struct pt_regs *, int), void *data) { struct imx_dma_channel *imxdma = &imx_dma_channels[dma_ch]; @@ -463,43 +466,53 @@ static irqreturn_t dma_err_handler(int irq, void *dev_id, struct pt_regs *regs) int i, disr = DISR; struct imx_dma_channel *channel; unsigned int err_mask = DBTOSR | DRTOSR | DSESR | DBOSR; + int errcode; - DISR = disr; + DISR = disr & err_mask; for (i = 0; i < IMX_DMA_CHANNELS; i++) { - channel = &imx_dma_channels[i]; - - if ((err_mask & 1 << i) && channel->name - && channel->err_handler) { - channel->err_handler(i, channel->data, regs); + if(!(err_mask & (1 << i))) continue; - } - - imx_dma_channels[i].sg = NULL; + channel = &imx_dma_channels[i]; + errcode = 0; if (DBTOSR & (1 << i)) { - printk(KERN_WARNING - "Burst timeout on channel %d (%s)\n", - i, channel->name); - DBTOSR |= (1 << i); + DBTOSR = (1 << i); + errcode |= IMX_DMA_ERR_BURST; } if (DRTOSR & (1 << i)) { - printk(KERN_WARNING - "Request timeout on channel %d (%s)\n", - i, channel->name); - DRTOSR |= (1 << i); + DRTOSR = (1 << i); + errcode |= IMX_DMA_ERR_REQUEST; } if (DSESR & (1 << i)) { - printk(KERN_WARNING - "Transfer timeout on channel %d (%s)\n", - i, channel->name); - DSESR |= (1 << i); + DSESR = (1 << i); + errcode |= IMX_DMA_ERR_TRANSFER; } if (DBOSR & (1 << i)) { - printk(KERN_WARNING - "Buffer overflow timeout on channel %d (%s)\n", - i, channel->name); - DBOSR |= (1 << i); + DBOSR = (1 << i); + errcode |= IMX_DMA_ERR_BUFFER; } + + /* + * The cleaning of @sg field would be questionable + * there, because its value can help to compute + * remaining/transfered bytes count in the handler + */ + /*imx_dma_channels[i].sg = NULL;*/ + + if (channel->name && channel->err_handler) { + channel->err_handler(i, channel->data, regs, errcode); + continue; + } + + imx_dma_channels[i].sg = NULL; + + printk(KERN_WARNING + "DMA timeout on channel %d (%s) -%s%s%s%s\n", + i, channel->name, + errcode&IMX_DMA_ERR_BURST? " burst":"", + errcode&IMX_DMA_ERR_REQUEST? " request":"", + errcode&IMX_DMA_ERR_TRANSFER? " transfer":"", + errcode&IMX_DMA_ERR_BUFFER? " buffer":""); } return IRQ_HANDLED; } -- cgit v1.2.3