On 10/30/2014 02:05 PM, Arnd Bergmann wrote:
On Thursday 30 October 2014 13:16:28 Mark Langsdorf wrote:
- /* Initialize dma_mask and coherent_dma_mask to 32-bits */
- ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
- if (ret)
- return ret;
+ /* Try setting the coherent_dma_mask to 64 bits, then try 32 bits */
+ if (sizeof(dma_addr_t) < 8 ||
+ dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) {
+ ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+ }
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
else
- dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+ dma_set_mask(&pdev->dev, pdev->dev.coherent_dma_mask);
hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
if (!hcd)
The logic here seems wrong: if dma_set_mask is successful, you
can rely on on dma_set_coherent_mask suceeding as well, but
not the other way round.
That's the order in the existing driver. Would you prefer I
switch it to:
if (sizeof(dma_addr_t) < 8 ||
dma_set_mask(&pdev->dev, DMA_BIT_MASK(64))) {
ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
if (ret)
return ret;
}
dma_set_coherent_mask(&pdev->dev, pdev->dev.dma_mask);
or based on the comment below:
ret = dma_set_mask(&pdev->dev, pdev->dev.dma_mask);
if (ret)
return ret;
dma_set_coherent_mask(&pdev->dev, pdev->dev.dma_mask);
I prefer this version but I don't know if it would work.
Also, we should no longer need to worry about the case where
pdev->dev.dma_mask is NULL, as this now gets initialized from
the DT setup.
I'm running this on a system with ACPI enabled and no DT. Does
that make a difference?
--Mark Langsdorf
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