[RESEND][PATCH] dma: edma: fix slave config dependency on direction

From: Matt Porter
Date: Thu Jan 10 2013 - 13:36:18 EST


The edma_slave_config() implementation depends on the
direction field such that it will not properly configure
a slave channel when called without direction set.

This fixes the implementation so that the slave config
is copied as is and prep_slave_sg() handles the
direction dependent handling. spi-omap2-mcspi and
omap_hsmmc both expose this bug as they configure the
slave channel config from a common path with an unconfigured
direction field.

Signed-off-by: Matt Porter <mporter@xxxxxx>
---
drivers/dma/edma.c | 55 ++++++++++++++++++++++++++--------------------------
1 file changed, 27 insertions(+), 28 deletions(-)

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 05aea3c..fdcf079 100644
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -69,9 +69,7 @@ struct edma_chan {
int ch_num;
bool alloced;
int slot[EDMA_MAX_SLOTS];
- dma_addr_t addr;
- int addr_width;
- int maxburst;
+ struct dma_slave_config cfg;
};

struct edma_cc {
@@ -178,29 +176,14 @@ static int edma_terminate_all(struct edma_chan *echan)
return 0;
}

-
static int edma_slave_config(struct edma_chan *echan,
- struct dma_slave_config *config)
+ struct dma_slave_config *cfg)
{
- if ((config->src_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES) ||
- (config->dst_addr_width > DMA_SLAVE_BUSWIDTH_4_BYTES))
+ if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES ||
+ cfg->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES)
return -EINVAL;

- if (config->direction == DMA_MEM_TO_DEV) {
- if (config->dst_addr)
- echan->addr = config->dst_addr;
- if (config->dst_addr_width)
- echan->addr_width = config->dst_addr_width;
- if (config->dst_maxburst)
- echan->maxburst = config->dst_maxburst;
- } else if (config->direction == DMA_DEV_TO_MEM) {
- if (config->src_addr)
- echan->addr = config->src_addr;
- if (config->src_addr_width)
- echan->addr_width = config->src_addr_width;
- if (config->src_maxburst)
- echan->maxburst = config->src_maxburst;
- }
+ memcpy(&echan->cfg, cfg, sizeof(echan->cfg));

return 0;
}
@@ -235,6 +218,9 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
struct edma_chan *echan = to_edma_chan(chan);
struct device *dev = chan->device->dev;
struct edma_desc *edesc;
+ dma_addr_t dev_addr;
+ enum dma_slave_buswidth dev_width;
+ u32 burst;
struct scatterlist *sg;
int i;
int acnt, bcnt, ccnt, src, dst, cidx;
@@ -243,7 +229,20 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
if (unlikely(!echan || !sgl || !sg_len))
return NULL;

- if (echan->addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
+ if (direction == DMA_DEV_TO_MEM) {
+ dev_addr = echan->cfg.src_addr;
+ dev_width = echan->cfg.src_addr_width;
+ burst = echan->cfg.src_maxburst;
+ } else if (direction == DMA_MEM_TO_DEV) {
+ dev_addr = echan->cfg.dst_addr;
+ dev_width = echan->cfg.dst_addr_width;
+ burst = echan->cfg.dst_maxburst;
+ } else {
+ dev_err(dev, "%s: bad direction?\n", __func__);
+ return NULL;
+ }
+
+ if (dev_width == DMA_SLAVE_BUSWIDTH_UNDEFINED) {
dev_err(dev, "Undefined slave buswidth\n");
return NULL;
}
@@ -275,14 +274,14 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
}
}

- acnt = echan->addr_width;
+ acnt = dev_width;

/*
* If the maxburst is equal to the fifo width, use
* A-synced transfers. This allows for large contiguous
* buffer transfers using only one PaRAM set.
*/
- if (echan->maxburst == 1) {
+ if (burst == 1) {
edesc->absync = false;
ccnt = sg_dma_len(sg) / acnt / (SZ_64K - 1);
bcnt = sg_dma_len(sg) / acnt - ccnt * (SZ_64K - 1);
@@ -302,7 +301,7 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(
*/
} else {
edesc->absync = true;
- bcnt = echan->maxburst;
+ bcnt = burst;
ccnt = sg_dma_len(sg) / (acnt * bcnt);
if (ccnt > (SZ_64K - 1)) {
dev_err(dev, "Exceeded max SG segment size\n");
@@ -313,13 +312,13 @@ static struct dma_async_tx_descriptor *edma_prep_slave_sg(

if (direction == DMA_MEM_TO_DEV) {
src = sg_dma_address(sg);
- dst = echan->addr;
+ dst = dev_addr;
src_bidx = acnt;
src_cidx = cidx;
dst_bidx = 0;
dst_cidx = 0;
} else {
- src = echan->addr;
+ src = dev_addr;
dst = sg_dma_address(sg);
src_bidx = 0;
src_cidx = 0;
--
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/