the following error pops up during "testusb -a -t 10"
| musb-hdrc musb-hdrc.1.auto: dma_pool_free buffer-128, f134e000/be842000 (bad dma)
hcd_buffer_create() creates a few buffers, the smallest has 32 bytes of
size. ARCH_KMALLOC_MINALIGN is set to 64 bytes. This combo results in
hcd_buffer_alloc() returning memory which is 32bytes aligned and it
might by identified by buffer_offset() as another buffer. This means the
buffer which is on a 32byte boundary will not get freed, instead it
tries to free another buffer with the error message.
This patch fixes the issue by creating the smallest DMA buffer with the
size of ARCH_DMA_MINALIGN. This will be either 32 or 64 bytes. If the
ARCH_DMA_MINALIGN is 128 (currently powerpc64, mips ip32, x86 pentium 4) then
it will create the first buffer with 128 bytes and will have only 3
buffers. There is a BUILD_BUG_ON() now in case someone has a minalign of
128 bytes or more.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
v1…v2: rewrite pool_max so it is less confusing.
drivers/usb/core/buffer.c | 12 ++++++++----
include/linux/usb/hcd.h | 8 ++++++--
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 684ef70dc09d..5ad5f71d6358 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -26,10 +26,13 @@ static const size_t pool_max[HCD_BUFFER_POOLS] = {
/* platforms without dma-friendly caches might need to
* prevent cacheline sharing...
*/
- 32,
- 128,
- 512,
- PAGE_SIZE / 2
+#if ARCH_KMALLOC_MINALIGN <= 32
+ 32, 128, 512, PAGE_SIZE / 2,
+#elif ARCH_KMALLOC_MINALIGN <= 64
+ 64, 128, 512, PAGE_SIZE / 2,
+#else
+ 128, 512, PAGE_SIZE / 2
+#endif
/* bigger --> allocate pages */
};
@@ -58,6 +61,7 @@ int hcd_buffer_create(struct usb_hcd *hcd)
!(hcd->driver->flags & HCD_LOCAL_MEM))
return 0;
+ BUILD_BUG_ON(ARCH_KMALLOC_MINALIGN > 128);
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
size = pool_max[i];
if (!size)
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index cd96a2bc3388..1e2234ca448d 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -23,6 +23,7 @@
#include <linux/rwsem.h>
#include <linux/interrupt.h>
+#include <linux/slab.h>
#define MAX_TOPO_LEVEL 6
@@ -171,8 +172,11 @@ struct usb_hcd {
struct usb_hcd *shared_hcd;
struct usb_hcd *primary_hcd;
-
-#define HCD_BUFFER_POOLS 4
+#if ARCH_KMALLOC_MINALIGN <= 64
+ #define HCD_BUFFER_POOLS 4
+#else
+ #define HCD_BUFFER_POOLS 3
+#endif
struct dma_pool *pool[HCD_BUFFER_POOLS];
int state;
--
2.1.3
--
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