From: Thierry Reding <treding@xxxxxxxxxx>
According to the TRM, the SD/MMC controller on Tegra124 supports 34-bit
addressing, but testing shows that this doesn't work. On a device which
has more than 2 GiB of RAM and LPAE enabled, buffer allocations can use
addresses above the 32-bit boundary.
One way to work around this would be to enable IOMMU physical to virtual
address translations for the SD/MMC controllers, but that's not easy to
implement without breaking existing use-cases. It's also not obvious why
34-bit addressing doesn't work as advertised. In order to fix this for
existing users, add the SDHCI_QUIRK2_BROKEN_64_BIT_DMA quirk for now.
Reported-by: Paul Kocialkowski <contact@xxxxxxxx>
Acked-by: Stephen Warren <swarren@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
Changes in v2:
- add comment with rationale for the quirk
- add various Acked-bys
drivers/mmc/host/sdhci-tegra.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 1e93dc4e303e..20b6ff5b4af1 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -391,6 +391,31 @@ static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
.pdata = &sdhci_tegra114_pdata,
};
+static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
+ .quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
+ SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
+ SDHCI_QUIRK_SINGLE_POWER_WRITE |
+ SDHCI_QUIRK_NO_HISPD_BIT |
+ SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC |
+ SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+ .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
+ /*
+ * The TRM states that the SD/MMC controller found on
+ * Tegra124 can address 34 bits (the maximum supported by
+ * the Tegra memory controller), but tests show that DMA
+ * to or from above 4 GiB doesn't work. This is possibly
+ * caused by missing programming, though it's not obvious
+ * what sequence is required. Mark 64-bit DMA broken for
+ * now to fix this for existing users (e.g. Nyan boards).
+ */
+ SDHCI_QUIRK2_BROKEN_64_BIT_DMA,
+ .ops = &tegra114_sdhci_ops,
+};
+
+static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
+ .pdata = &sdhci_tegra124_pdata,
+};
+
static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
@@ -408,7 +433,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
static const struct of_device_id sdhci_tegra_dt_match[] = {
{ .compatible = "nvidia,tegra210-sdhci", .data = &soc_data_tegra210 },
- { .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra114 },
+ { .compatible = "nvidia,tegra124-sdhci", .data = &soc_data_tegra124 },
{ .compatible = "nvidia,tegra114-sdhci", .data = &soc_data_tegra114 },
{ .compatible = "nvidia,tegra30-sdhci", .data = &soc_data_tegra30 },
{ .compatible = "nvidia,tegra20-sdhci", .data = &soc_data_tegra20 },
--
2.9.3
--
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