diff options
| author | Zhang Wei <wei.zhang@freescale.com> | 2008-03-19 04:45:00 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2008-03-19 03:00:59 +0300 |
| commit | f79abb627f033c85a6088231f20c85bc4a9bd757 (patch) | |
| tree | 151538a3a33026ae516606240a13404d1f1e7037 | |
| parent | f920bb6f5fe21047e669381fe4dd346f6a9d3562 (diff) | |
| download | linux-f79abb627f033c85a6088231f20c85bc4a9bd757.tar.xz | |
fsldma: Fix the DMA halt when using DMA_INTERRUPT async_tx transfer.
The DMA_INTERRUPT async_tx is a NULL transfer, thus the BCR(count register)
is 0. When the transfer started with a byte count of zero, the DMA
controller will triger a PE(programming error) event and halt, not a normal
interrupt. I add special codes for PE event and DMA_INTERRUPT
async_tx testing.
Signed-off-by: Zhang Wei <wei.zhang@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | drivers/dma/fsldma.c | 30 | ||||
| -rw-r--r-- | drivers/dma/fsldma.h | 1 |
2 files changed, 31 insertions, 0 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index ad2f938597e2..72692309398a 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -123,6 +123,11 @@ static dma_addr_t get_ndar(struct fsl_dma_chan *fsl_chan) return DMA_IN(fsl_chan, &fsl_chan->reg_base->ndar, 64); } +static u32 get_bcr(struct fsl_dma_chan *fsl_chan) +{ + return DMA_IN(fsl_chan, &fsl_chan->reg_base->bcr, 32); +} + static int dma_is_idle(struct fsl_dma_chan *fsl_chan) { u32 sr = get_sr(fsl_chan); @@ -426,6 +431,9 @@ fsl_dma_prep_interrupt(struct dma_chan *chan) new->async_tx.cookie = -EBUSY; new->async_tx.ack = 0; + /* Insert the link descriptor to the LD ring */ + list_add_tail(&new->node, &new->async_tx.tx_list); + /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(fsl_chan, new); @@ -701,6 +709,23 @@ static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data) if (stat & FSL_DMA_SR_TE) dev_err(fsl_chan->dev, "Transfer Error!\n"); + /* Programming Error + * The DMA_INTERRUPT async_tx is a NULL transfer, which will + * triger a PE interrupt. + */ + if (stat & FSL_DMA_SR_PE) { + dev_dbg(fsl_chan->dev, "event: Programming Error INT\n"); + if (get_bcr(fsl_chan) == 0) { + /* BCR register is 0, this is a DMA_INTERRUPT async_tx. + * Now, update the completed cookie, and continue the + * next uncompleted transfer. + */ + fsl_dma_update_completed_cookie(fsl_chan); + fsl_chan_xfer_ld_queue(fsl_chan); + } + stat &= ~FSL_DMA_SR_PE; + } + /* If the link descriptor segment transfer finishes, * we will recycle the used descriptor. */ @@ -841,6 +866,11 @@ static int fsl_dma_self_test(struct fsl_dma_chan *fsl_chan) tx3 = fsl_dma_prep_memcpy(chan, dma_dest, dma_src, test_size / 4, 0); async_tx_ack(tx3); + /* Interrupt tx test */ + tx1 = fsl_dma_prep_interrupt(chan); + async_tx_ack(tx1); + cookie = fsl_dma_tx_submit(tx1); + /* Test exchanging the prepared tx sort */ cookie = fsl_dma_tx_submit(tx3); cookie = fsl_dma_tx_submit(tx2); diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h index ba78c42121ba..fddd6aee2a63 100644 --- a/drivers/dma/fsldma.h +++ b/drivers/dma/fsldma.h @@ -40,6 +40,7 @@ #define FSL_DMA_MR_EOTIE 0x00000080 #define FSL_DMA_SR_CH 0x00000020 +#define FSL_DMA_SR_PE 0x00000010 #define FSL_DMA_SR_CB 0x00000004 #define FSL_DMA_SR_TE 0x00000080 #define FSL_DMA_SR_EOSI 0x00000002 |