[PATCH V2] mmc: sdhci-acpi: Add 64-bit DMA support

Adrian Hunter
2014-10-28T08:38:49Z

Set the DMA mask during the first call to ->enable_dma() to
make use of the SDHCI_USE_64_BIT_DMA flag.

This patch is dependent on
commit 8a2f38ddfeb526c30b3ec209468172a30a38d996 ("ACPI / platform: provide default DMA mask")
which provides the dev->dma_mask pointer without
which dma_set_mask_and_coherent() will always fail.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/host/sdhci-acpi.c | 40 ++++++++++++++++++++++++----------------
1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index 9cccc0e..3109763 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -76,6 +76,7 @@ struct sdhci_acpi_host {
const struct sdhci_acpi_slot *slot;
struct platform_device *pdev;
bool use_runtime_pm;
+ bool dma_setup;
};

static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
@@ -85,7 +86,29 @@ static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)

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;
}

static void sdhci_acpi_int_hw_reset(struct sdhci_host *host)
@@ -305,21 +328,6 @@ static int sdhci_acpi_probe(struct platform_device *pdev)
goto err_free;
}

- if (!dev->dma_mask) {
- u64 dma_mask;
-
- if (sdhci_readl(host, SDHCI_CAPABILITIES) & SDHCI_CAN_64BIT) {
- /* 64-bit DMA is not supported at present */
- dma_mask = DMA_BIT_MASK(32);
- } else {
- dma_mask = DMA_BIT_MASK(32);
- }
-
- err = dma_coerce_mask_and_coherent(dev, dma_mask);
- if (err)
- goto err_free;
- }
-
if (c->slot) {
if (c->slot->probe_slot) {
err = c->slot->probe_slot(pdev, hid, uid);
--
1.9.1