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path: root/drivers/mmc/host/sdhci-iproc.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-iproc.c')
-rw-r--r--drivers/mmc/host/sdhci-iproc.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-iproc.c b/drivers/mmc/host/sdhci-iproc.c
index ddeaf8e1f72f..b9eb2ec61a83 100644
--- a/drivers/mmc/host/sdhci-iproc.c
+++ b/drivers/mmc/host/sdhci-iproc.c
@@ -173,6 +173,23 @@ static unsigned int sdhci_iproc_get_max_clock(struct sdhci_host *host)
return pltfm_host->clock;
}
+/*
+ * There is a known bug on BCM2711's SDHCI core integration where the
+ * controller will hang when the difference between the core clock and the bus
+ * clock is too great. Specifically this can be reproduced under the following
+ * conditions:
+ *
+ * - No SD card plugged in, polling thread is running, probing cards at
+ * 100 kHz.
+ * - BCM2711's core clock configured at 500MHz or more
+ *
+ * So we set 200kHz as the minimum clock frequency available for that SoC.
+ */
+static unsigned int sdhci_iproc_bcm2711_get_min_clock(struct sdhci_host *host)
+{
+ return 200000;
+}
+
static const struct sdhci_ops sdhci_iproc_ops = {
.set_clock = sdhci_set_clock,
.get_max_clock = sdhci_iproc_get_max_clock,
@@ -271,6 +288,7 @@ static const struct sdhci_ops sdhci_iproc_bcm2711_ops = {
.set_clock = sdhci_set_clock,
.set_power = sdhci_set_power_and_bus_voltage,
.get_max_clock = sdhci_iproc_get_max_clock,
+ .get_min_clock = sdhci_iproc_bcm2711_get_min_clock,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,