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authorMarkus Klotzbücher <mk@denx.de>2008-07-10 14:47:09 +0200
committerWolfgang Denk <wd@denx.de>2008-07-10 21:47:44 +0200
commit3d71c81a9bb03f866a1e98da96363ef3f46c76b3 (patch)
treed238a1da6f5a90056b20cbbf017c5b502327a64f
parente0320b1ebec13755911a53b0af12cbf3e5e49a65 (diff)
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USB: shutdown USB before booting
This patch fixes a potentially serious issue related to USB which was discouvered by Martin Krause <martin.krause@tqs.de> and fixed for ARM920T. Martin wrote: Turn off USB to prevent the host controller from writing to the SDRAM while Linux is booting. This could happen, because the HCCA (Host Controller Communication Area) lies within the SDRAM and the host controller writes continously to this area (as busmaster!), for example to increase the HccaFrameNumber variable, which happens every 1 ms. This is a slightly modified version of the patch in order to shutdown USB when booting on all architectures. Signed-off-by: Markus Klotzbuecher <mk@denx.de>
-rw-r--r--common/cmd_bootm.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index f701ab6..da38c32 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -36,6 +36,10 @@
#include <lmb.h>
#include <asm/byteorder.h>
+#if (CONFIG_COMMANDS & CFG_CMD_USB)
+#include <usb.h>
+#endif
+
#ifdef CFG_HUSH_PARSER
#include <hush.h>
#endif
@@ -213,6 +217,20 @@ int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
*/
iflag = disable_interrupts();
+#if (CONFIG_COMMANDS & CFG_CMD_USB)
+ /*
+ * turn off USB to prevent the host controller from writing to the
+ * SDRAM while Linux is booting. This could happen (at least for OHCI
+ * controller), because the HCCA (Host Controller Communication Area)
+ * lies within the SDRAM and the host controller writes continously to
+ * this area (as busmaster!). The HccaFrameNumber is for example
+ * updated every 1 ms within the HCCA structure in SDRAM! For more
+ * details see the OpenHCI specification.
+ */
+ usb_stop();
+#endif
+
+
#ifdef CONFIG_AMIGAONEG3SE
/*
* We've possible left the caches enabled during