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authorMike Frysinger <vapier@gentoo.org>2010-07-23 11:34:49 -0400
committerMike Frysinger <vapier@gentoo.org>2010-07-25 15:17:27 -0400
commit5079d8bbad77bf21ecc5f17e05141f04cfaaabb3 (patch)
tree74aa53dfe6f07de94cefd9c63b2fa57074479921 /arch/blackfin
parentf5ff2030bfd7b1bc1ab859f90d285a861dca715f (diff)
downloadu-boot-linaro-stable-5079d8bbad77bf21ecc5f17e05141f04cfaaabb3.tar.gz
Blackfin: jtag-console: robustify against missing peer
If the other side isn't listening, we should reset the state to ignore the whole message and not just the part we missed. This makes it easier to connect at any time to the jtag console without worrying about the two sides getting out of sync and thus sending garbage back and forth. Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Diffstat (limited to 'arch/blackfin')
-rw-r--r--arch/blackfin/cpu/jtag-console.c40
1 files changed, 32 insertions, 8 deletions
diff --git a/arch/blackfin/cpu/jtag-console.c b/arch/blackfin/cpu/jtag-console.c
index 1cd619f10..46b30a0f8 100644
--- a/arch/blackfin/cpu/jtag-console.c
+++ b/arch/blackfin/cpu/jtag-console.c
@@ -1,7 +1,7 @@
/*
* jtag-console.c - console driver over Blackfin JTAG
*
- * Copyright (c) 2008 Analog Devices Inc.
+ * Copyright (c) 2008-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
@@ -10,23 +10,37 @@
#include <stdio_dev.h>
#include <asm/blackfin.h>
+static inline uint32_t bfin_write_emudat(uint32_t emudat)
+{
+ __asm__ __volatile__("emudat = %0;" : : "d"(emudat));
+ return emudat;
+}
+
+static inline uint32_t bfin_read_emudat(void)
+{
+ uint32_t emudat;
+ __asm__ __volatile__("%0 = emudat;" : "=d"(emudat));
+ return emudat;
+}
+
#ifndef CONFIG_JTAG_CONSOLE_TIMEOUT
# define CONFIG_JTAG_CONSOLE_TIMEOUT 500
#endif
/* The Blackfin tends to be much much faster than the JTAG hardware. */
-static void jtag_write_emudat(uint32_t emudat)
+static bool jtag_write_emudat(uint32_t emudat)
{
static bool overflowed = false;
ulong timeout = get_timer(0) + CONFIG_JTAG_CONSOLE_TIMEOUT;
while (bfin_read_DBGSTAT() & 0x1) {
if (overflowed)
- return;
+ return overflowed;
if (timeout < get_timer(0))
overflowed = true;
}
overflowed = false;
- __asm__ __volatile__("emudat = %0;" : : "d"(emudat));
+ bfin_write_emudat(emudat);
+ return overflowed;
}
/* Transmit a buffer. The format is:
* [32bit length][actual data]
@@ -39,11 +53,21 @@ static void jtag_send(const char *c, uint32_t len)
return;
/* First send the length */
- jtag_write_emudat(len);
+ if (jtag_write_emudat(len))
+ return;
/* Then send the data */
- for (i = 0; i < len; i += 4)
- jtag_write_emudat((c[i] << 0) | (c[i+1] << 8) | (c[i+2] << 16) | (c[i+3] << 24));
+ for (i = 0; i < len; i += 4) {
+ uint32_t emudat =
+ (c[i + 0] << 0) |
+ (c[i + 1] << 8) |
+ (c[i + 2] << 16) |
+ (c[i + 3] << 24);
+ if (jtag_write_emudat(emudat)) {
+ bfin_write_emudat(0);
+ return;
+ }
+ }
}
static void jtag_putc(const char c)
{
@@ -88,7 +112,7 @@ static int jtag_getc(void)
/* wait for new data ! */
while (!jtag_tstc_dbg())
continue;
- __asm__("%0 = emudat;" : "=d"(emudat));
+ emudat = bfin_read_emudat();
if (inbound_len == 0) {
/* grab the length */