Hi All,
We still need the attached patch for our onboard SD card interface
[1,2]. Could you please add this patch to the tree?
Thanks,
Christian
[1] https://www.spinics.net/lists/linux-mmc/msg56211.html
[2]
http://forum.hyperion-entertainment.com/viewtopic.php?f=58&t=4349&start=20#p49012
diff -rupN a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
--- a/arch/powerpc/kernel/setup-common.c 2019-12-03 18:05:52.436070217 +0100
+++ b/arch/powerpc/kernel/setup-common.c 2019-12-03 18:03:20.316629696 +0100
@@ -780,6 +780,22 @@ static int __init check_cache_coherency(
late_initcall(check_cache_coherency);
#endif /* CONFIG_CHECK_CACHE_COHERENCY */
+#ifndef CONFIG_NOT_COHERENT_CACHE
+/*
+ * For historical reasons powerpc kernels are built with hard wired knowledge of
+ * whether or not DMA accesses are cache coherent. Additionally device trees on
+ * powerpc do not typically support the dma-coherent property.
+ *
+ * So when we know that DMA is coherent, override arch_of_dma_is_coherent() to
+ * tell the drivers/of code that all devices are coherent regardless of whether
+ * they have a dma-coherent property.
+ */
+bool arch_of_dma_is_coherent(struct device_node *np)
+{
+ return true;
+}
+#endif
+
#ifdef CONFIG_DEBUG_FS
struct dentry *powerpc_debugfs_root;
EXPORT_SYMBOL(powerpc_debugfs_root);
diff -rupN a/drivers/of/address.c b/drivers/of/address.c
--- a/drivers/of/address.c 2019-12-03 18:05:57.332052212 +0100
+++ b/drivers/of/address.c 2019-12-03 18:03:20.320629681 +0100
@@ -990,6 +990,14 @@ out:
return ret;
}
+/*
+ * arch_of_dma_is_coherent - Arch hook to determine if device is coherent for DMA
+ */
+bool __weak arch_of_dma_is_coherent(struct device_node *np)
+{
+ return false;
+}
+
/**
* of_dma_is_coherent - Check if device is coherent
* @np: device node
@@ -999,8 +1007,12 @@ out:
*/
bool of_dma_is_coherent(struct device_node *np)
{
- struct device_node *node = of_node_get(np);
+ struct device_node *node;
+
+ if (arch_of_dma_is_coherent(np))
+ return true;
+ np = of_node_get(np);
while (node) {
if (of_property_read_bool(node, "dma-coherent")) {
of_node_put(node);
