On 28/10/14 11:43, Arnd Bergmann wrote: > On Tuesday 28 October 2014 10:37:20 Adrian Hunter wrote: >> static int sdhci_acpi_enable_dma(struct sdhci_host *host) >> { >> - return 0; >> + struct sdhci_acpi_host *c = sdhci_priv(host); >> + struct device *dev = &c->pdev->dev; >> + int err = -1; >> + >> + if (c->dma_setup) >> + return 0; >> + >> + if (host->flags & SDHCI_USE_64_BIT_DMA) { >> + if (host->quirks2 & SDHCI_QUIRK2_BROKEN_64_BIT_DMA) { >> + host->flags &= ~SDHCI_USE_64_BIT_DMA; >> + } else { >> + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); >> + if (err) >> + dev_warn(dev, "Failed to set 64-bit DMA mask\n"); >> + } >> + } >> + >> + if (err) >> + err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); >> + >> + c->dma_setup = !err; >> + >> + return err; >> } >> > > I don't think it's worth a dev_warn() message (maybe dev_info), there is nothing It is worth a dev_warn because 32-bit DMA can allocate memory for bounce buffers which jeopardizes memory reclaim. > wrong in this case, but you probably have to clear the SDHCI_USE_64_BIT_DMA to > ensure that the driver won't try to to use the 64-bit DMA if the mask is not set. 64-bit DMA will work with a 32-bit DMA mask so there is no need. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html