2.6.25-stable review patch. If anyone has any objections, please let us know. ------------------ From: Michael Buesch commit 1033b3ea11820ea1fb1b877207bd6724e9aaedc3 upstream Some mainboards/CPUs don't allow DMA masks bigger than a certain limit. Some VIA crap^h^h^h^hdevices have an upper limit of 0xFFFFFFFF. So in this case a 64-bit b43 device would always fail to acquire the mask. Implement a workaround to fallback to lower DMA mask, as we can always also support a lower mask. Signed-off-by: Michael Buesch Signed-off-by: John W. Linville --- drivers/net/wireless/b43/dma.c | 73 +++++++++++++++++++++++++++++------------ 1 file changed, 52 insertions(+), 21 deletions(-) --- a/drivers/net/wireless/b43/dma.c +++ b/drivers/net/wireless/b43/dma.c @@ -822,6 +822,18 @@ static u64 supported_dma_mask(struct b43 return DMA_30BIT_MASK; } +static enum b43_dmatype dma_mask_to_engine_type(u64 dmamask) +{ + if (dmamask == DMA_30BIT_MASK) + return B43_DMA_30BIT; + if (dmamask == DMA_32BIT_MASK) + return B43_DMA_32BIT; + if (dmamask == DMA_64BIT_MASK) + return B43_DMA_64BIT; + B43_WARN_ON(1); + return B43_DMA_30BIT; +} + /* Main initialization function. */ static struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev, @@ -982,6 +994,42 @@ void b43_dma_free(struct b43_wldev *dev) dma->tx_ring0 = NULL; } +static int b43_dma_set_mask(struct b43_wldev *dev, u64 mask) +{ + u64 orig_mask = mask; + bool fallback = 0; + int err; + + /* Try to set the DMA mask. If it fails, try falling back to a + * lower mask, as we can always also support a lower one. */ + while (1) { + err = ssb_dma_set_mask(dev->dev, mask); + if (!err) + break; + if (mask == DMA_64BIT_MASK) { + mask = DMA_32BIT_MASK; + fallback = 1; + continue; + } + if (mask == DMA_32BIT_MASK) { + mask = DMA_30BIT_MASK; + fallback = 1; + continue; + } + b43err(dev->wl, "The machine/kernel does not support " + "the required %u-bit DMA mask\n", + (unsigned int)dma_mask_to_engine_type(orig_mask)); + return -EOPNOTSUPP; + } + if (fallback) { + b43info(dev->wl, "DMA mask fallback from %u-bit to %u-bit\n", + (unsigned int)dma_mask_to_engine_type(orig_mask), + (unsigned int)dma_mask_to_engine_type(mask)); + } + + return 0; +} + int b43_dma_init(struct b43_wldev *dev) { struct b43_dma *dma = &dev->dma; @@ -991,27 +1039,10 @@ int b43_dma_init(struct b43_wldev *dev) enum b43_dmatype type; dmamask = supported_dma_mask(dev); - switch (dmamask) { - default: - B43_WARN_ON(1); - case DMA_30BIT_MASK: - type = B43_DMA_30BIT; - break; - case DMA_32BIT_MASK: - type = B43_DMA_32BIT; - break; - case DMA_64BIT_MASK: - type = B43_DMA_64BIT; - break; - } - err = ssb_dma_set_mask(dev->dev, dmamask); - if (err) { - b43err(dev->wl, "The machine/kernel does not support " - "the required DMA mask (0x%08X%08X)\n", - (unsigned int)((dmamask & 0xFFFFFFFF00000000ULL) >> 32), - (unsigned int)(dmamask & 0x00000000FFFFFFFFULL)); - return -EOPNOTSUPP; - } + type = dma_mask_to_engine_type(dmamask); + err = b43_dma_set_mask(dev, dmamask); + if (err) + return err; err = -ENOMEM; /* setup TX DMA channels. */ -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/