Hi,
Hi,
[...]
+/*
+ * We have seen MMC DMA transfers read corrupted data from SDRAM
when a burst
+ * interval ends at physical address 0x10000000. To avoid this
problem, we
+ * remove the final page of low memory from the memory map.
+ */
+void __init jz4770_reserve_unsafe_for_dma(void)
+{
+ int i;
+
+ for (i = 0; i < boot_mem_map.nr_map; i++) {
+ struct boot_mem_map_entry *entry = boot_mem_map.map
+ i;
+
+ if (entry->type != BOOT_MEM_RAM)
+ continue;
+
+ if (entry->addr + entry->size != 0x10000000)
+ continue;
+
+ entry->size -= PAGE_SIZE;
+ break;
+ }
+}
+
Just a wild idea (probably bad too). Changing the memory node in the
device tree to skip this physical address would work I think. What is
your opinion about that?
I guess it would work as well, but I don't think this fix should be in
devicetree.
-Paul
