[ARM] dma: RiscPC: don't modify DMA SG entries
We should not be modifying the scatterlist passed to us from the driver code; doing so breaks assumptions made by the DMA API code, and could cause problems if the driver retries a transfer using an old scatterlist. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
parent
308d333ad6
commit
fa4e998999
|
@ -32,6 +32,8 @@ struct iomd_dma {
|
|||
unsigned long base; /* Controller base address */
|
||||
int irq; /* Controller IRQ */
|
||||
struct scatterlist cur_sg; /* Current controller buffer */
|
||||
dma_addr_t dma_addr;
|
||||
unsigned int dma_len;
|
||||
};
|
||||
|
||||
#if 0
|
||||
|
@ -57,10 +59,10 @@ static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
|
|||
unsigned long end, offset, flags = 0;
|
||||
|
||||
if (idma->dma.sg) {
|
||||
sg->dma_address = idma->dma.sg->dma_address;
|
||||
sg->dma_address = idma->dma_addr;
|
||||
offset = sg->dma_address & ~PAGE_MASK;
|
||||
|
||||
end = offset + idma->dma.sg->length;
|
||||
end = offset + idma->dma_len;
|
||||
|
||||
if (end > PAGE_SIZE)
|
||||
end = PAGE_SIZE;
|
||||
|
@ -70,12 +72,14 @@ static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
|
|||
|
||||
sg->length = end - TRANSFER_SIZE;
|
||||
|
||||
idma->dma.sg->length -= end - offset;
|
||||
idma->dma.sg->dma_address += end - offset;
|
||||
idma->dma_len -= end - offset;
|
||||
idma->dma_addr += end - offset;
|
||||
|
||||
if (idma->dma.sg->length == 0) {
|
||||
if (idma->dma_len == 0) {
|
||||
if (idma->dma.sgcount > 1) {
|
||||
idma->dma.sg = sg_next(idma->dma.sg);
|
||||
idma->dma_addr = idma->dma.sg->dma_address;
|
||||
idma->dma_len = idma->dma.sg->length;
|
||||
idma->dma.sgcount--;
|
||||
} else {
|
||||
idma->dma.sg = NULL;
|
||||
|
|
Loading…
Reference in a new issue