On 13/02/14 02:49, Patrick Wood wrote:
On Tuesday, February 11, 2014 2:11:59 PM UTC-5, Siarhei Siamashka wrote:
The commit 1e205f75658cb0cf3addc28ddaa9912ca9ce14e8 happened to
break broken CedarX media players on the systems with 2GB of RAM
(Cubietruck). The problem is that some CedarX userland code (used
in VLC and XBMC together with proprietary blobs) already feeds
bus addresses to the sunxi disp ioctls, while physical addresses
are expected there. The open source libvdpau-sunxi does not have
such bugs.
This patch avoids phys->bus conversion if the address passed to
the __phys_to_bus macro is already obviously a bus address.
While the right solution would be to hunt down and fix all the
userland offenders, this may be difficult in practice. For example
when dealing with Android images and trying to provide a drop-in
kernel replacement for them.
Signed-off-by: Siarhei Siamashka <[email protected]
<javascript:>>
---
arch/arm/plat-sunxi/include/plat/memory.h | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/arch/arm/plat-sunxi/include/plat/memory.h
b/arch/arm/plat-sunxi/include/plat/memory.h
index 42a4afa..3a94fe6 100644
--- a/arch/arm/plat-sunxi/include/plat/memory.h
+++ b/arch/arm/plat-sunxi/include/plat/memory.h
@@ -30,7 +30,23 @@
/* default ATAG_MEM size */
#define MEM_SIZE (512*1024*1024)
-#define __phys_to_bus(x) ((x) - PLAT_PHYS_OFFSET)
+/*
+ * HACK: if 'x' argument is lower than PLAT_PHYS_OFFSET in the
'__phys_to_bus'
+ * macro (which is incorrect by itself), then we know that
something is
+ * wrong. Most likely 'x' is already a bus address (result
of a conversion
+ * of some physical address belonging to the first 1GB of
DRAM). Not much
+ * harm is done if we just keep it as-is instead of
wrapping around into
+ * the 0xC0000000-0xFFFFFFFF range. The typical offenders
are the CedarX
+ * userland wrappers around proprietary blobs, which mess
up the address
+ * arithmetics and may introduce an arbitrary address
offset (this offset
+ * is a multiple of 0x40000000). As we have little control
over the blobs
+ * used in Android, this hack may workaround some issues
for the users
+ * of the systems with 2GB of RAM (the adverse effects of a
multiple of
+ * 0x40000000 address calculation bugs only show up on such
systems).
+ */
+
+#define __phys_to_bus(x) ((u32)(x) < PLAT_PHYS_OFFSET ? (x) : \
+ (x) - PLAT_PHYS_OFFSET)
#define __bus_to_phys(x) ((x) + PLAT_PHYS_OFFSET)
#endif
--
1.8.3.2
Works for me on a 2GB CT.
thank you, applied on sunxi-3.4 and stage/sunxi-3.4
cheers,
Alejandro
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