mirror of https://gitee.com/openkylin/linux.git
b43: use 8K buffers for 64-bit DMA to workaround hardware bug
Signed-off-by: Rafał Miłecki <zajec5@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
parent
996bc370fa
commit
14a8083e67
|
@ -419,26 +419,34 @@ static int alloc_ringmemory(struct b43_dmaring *ring)
|
|||
gfp_t flags = GFP_KERNEL;
|
||||
|
||||
/* The specs call for 4K buffers for 30- and 32-bit DMA with 4K
|
||||
* alignment and 8K buffers for 64-bit DMA with 8K alignment. Testing
|
||||
* has shown that 4K is sufficient for the latter as long as the buffer
|
||||
* does not cross an 8K boundary.
|
||||
*
|
||||
* alignment and 8K buffers for 64-bit DMA with 8K alignment.
|
||||
* In practice we could use smaller buffers for the latter, but the
|
||||
* alignment is really important because of the hardware bug. If bit
|
||||
* 0x00001000 is used in DMA address, some hardware (like BCM4331)
|
||||
* copies that bit into B43_DMA64_RXSTATUS and we get false values from
|
||||
* B43_DMA64_RXSTATDPTR. Let's just use 8K buffers even if we don't use
|
||||
* more than 256 slots for ring.
|
||||
*/
|
||||
u16 ring_mem_size = (ring->type == B43_DMA_64BIT) ?
|
||||
B43_DMA64_RINGMEMSIZE : B43_DMA32_RINGMEMSIZE;
|
||||
|
||||
ring->descbase = dma_alloc_coherent(ring->dev->dev->dma_dev,
|
||||
B43_DMA_RINGMEMSIZE,
|
||||
&(ring->dmabase), flags);
|
||||
ring_mem_size, &(ring->dmabase),
|
||||
flags);
|
||||
if (!ring->descbase) {
|
||||
b43err(ring->dev->wl, "DMA ringmemory allocation failed\n");
|
||||
return -ENOMEM;
|
||||
}
|
||||
memset(ring->descbase, 0, B43_DMA_RINGMEMSIZE);
|
||||
memset(ring->descbase, 0, ring_mem_size);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void free_ringmemory(struct b43_dmaring *ring)
|
||||
{
|
||||
dma_free_coherent(ring->dev->dev->dma_dev, B43_DMA_RINGMEMSIZE,
|
||||
u16 ring_mem_size = (ring->type == B43_DMA_64BIT) ?
|
||||
B43_DMA64_RINGMEMSIZE : B43_DMA32_RINGMEMSIZE;
|
||||
dma_free_coherent(ring->dev->dev->dma_dev, ring_mem_size,
|
||||
ring->descbase, ring->dmabase);
|
||||
}
|
||||
|
||||
|
|
|
@ -161,7 +161,8 @@ struct b43_dmadesc_generic {
|
|||
} __packed;
|
||||
|
||||
/* Misc DMA constants */
|
||||
#define B43_DMA_RINGMEMSIZE PAGE_SIZE
|
||||
#define B43_DMA32_RINGMEMSIZE 4096
|
||||
#define B43_DMA64_RINGMEMSIZE 8192
|
||||
/* Offset of frame with actual data */
|
||||
#define B43_DMA0_RX_FW598_FO 38
|
||||
#define B43_DMA0_RX_FW351_FO 30
|
||||
|
|
Loading…
Reference in New Issue