From fa3e686a34f4c33de31a128cc36def0b466bfe1a Mon Sep 17 00:00:00 2001
From: Pavel Pisa <ppisa@pikron.com>
Date: Thu, 22 Jun 2006 22:21:03 +0100
Subject: [PATCH] [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 <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mach-imx/dma.c | 65 ++++++++++++++++++------------
include/asm-arm/arch-imx/imx-dma.h | 8 +++-
2 files changed, 45 insertions(+), 28 deletions(-)
diff --git a/arch/arm/mach-imx/dma.c b/arch/arm/mach-imx/dma.c
index 4ca51dcf13a..36578871ecc 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 <pisa@cmp.felk.cvut.cz>
+ * 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;
}
diff --git a/include/asm-arm/arch-imx/imx-dma.h b/include/asm-arm/arch-imx/imx-dma.h
index f2063c1d610..599f03e5a9e 100644
--- a/include/asm-arm/arch-imx/imx-dma.h
+++ b/include/asm-arm/arch-imx/imx-dma.h
@@ -46,7 +46,7 @@
struct imx_dma_channel {
const char *name;
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 errcode);
void *data;
dmamode_t dma_mode;
struct scatterlist *sg;
@@ -58,6 +58,10 @@ struct imx_dma_channel {
extern struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS];
+#define IMX_DMA_ERR_BURST 1
+#define IMX_DMA_ERR_REQUEST 2
+#define IMX_DMA_ERR_TRANSFER 4
+#define IMX_DMA_ERR_BUFFER 8
/* The type to distinguish channel numbers parameter from ordinal int type */
typedef int imx_dmach_t;
@@ -74,7 +78,7 @@ 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 *data);
+ void (*err_handler) (int, void *, struct pt_regs *, int), void *data);
void imx_dma_enable(imx_dmach_t dma_ch);
--
2.41.3