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authorKyösti Mälkki <kyosti.malkki@gmail.com>2013-08-12 16:11:34 +0300
committerKyösti Mälkki <kyosti.malkki@gmail.com>2013-08-23 05:02:54 +0200
commitd79914008abbc3eea4738d702ea7f3256e13327a (patch)
treecab2079aac864d82f10466ee5a058c4aa11407c3
parent8ff3d68e93c74d82dc289036347c3da74c395c88 (diff)
downloadcoreboot-d79914008abbc3eea4738d702ea7f3256e13327a.tar.xz
usbdebug: Block recursive calls of printk
When we create low-level debugging of EHCI controller registers, we call printk() within printk(). In ramstage this would leave us with deadlock waiting on the console spinlock. Change-Id: Idbe029af9af76de27094bb2964c60d9ccfdd96e6 Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-on: http://review.coreboot.org/3860 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
-rw-r--r--src/lib/usbdebug.c54
1 files changed, 44 insertions, 10 deletions
diff --git a/src/lib/usbdebug.c b/src/lib/usbdebug.c
index 4cd2987d6f..a5d3c37027 100644
--- a/src/lib/usbdebug.c
+++ b/src/lib/usbdebug.c
@@ -33,6 +33,7 @@
#define DBGP_EP_VALID (1<<0)
#define DBGP_EP_ENABLED (1<<1)
+#define DBGP_EP_BUSY (1<<2)
#define DBGP_EP_STATMASK (DBGP_EP_VALID | DBGP_EP_ENABLED)
struct dbgp_pipe
@@ -44,8 +45,9 @@ struct dbgp_pipe
};
#define DBGP_MAX_ENDPOINTS 4
-#define DBGP_CONSOLE_EPOUT 0
-#define DBGP_CONSOLE_EPIN 1
+#define DBGP_SETUP_EP0 0 /* Compulsory endpoint 0. */
+#define DBGP_CONSOLE_EPOUT 1
+#define DBGP_CONSOLE_EPIN 2
struct ehci_debug_info {
u8 devnum;
@@ -58,7 +60,9 @@ struct ehci_debug_info {
};
#if CONFIG_DEBUG_USBDEBUG
-# define dprintk(LEVEL, args...) printk(LEVEL, args)
+static int dbgp_enabled(void);
+# define dprintk(LEVEL, args...) \
+ do { if (!dbgp_enabled()) printk(LEVEL, ##args); } while (0)
#else
# define dprintk(LEVEL, args...) do {} while(0)
#endif
@@ -580,6 +584,7 @@ try_next_port:
info->ep_pipe[DBGP_CONSOLE_EPOUT].endpoint = dbgp_desc.bDebugOutEndpoint;
info->ep_pipe[DBGP_CONSOLE_EPIN].endpoint = dbgp_desc.bDebugInEndpoint;
+ info->ep_pipe[DBGP_SETUP_EP0].status |= DBGP_EP_ENABLED | DBGP_EP_VALID;
info->ep_pipe[DBGP_CONSOLE_EPOUT].status |= DBGP_EP_ENABLED | DBGP_EP_VALID;
info->ep_pipe[DBGP_CONSOLE_EPIN].status |= DBGP_EP_ENABLED | DBGP_EP_VALID;
return 0;
@@ -606,23 +611,52 @@ next_debug_port:
return -10;
}
+#if CONFIG_DEBUG_USBDEBUG
+static int dbgp_enabled(void)
+{
+ struct dbgp_pipe *globals = &dbgp_ehci_info()->ep_pipe[DBGP_SETUP_EP0];
+ return (globals->status & DBGP_EP_ENABLED);
+}
+#endif
+
+static int dbgp_try_get(struct dbgp_pipe *pipe)
+{
+ struct dbgp_pipe *globals = &dbgp_ehci_info()->ep_pipe[DBGP_SETUP_EP0];
+ if (!dbgp_ep_is_active(pipe) || (globals->status & DBGP_EP_BUSY))
+ return 0;
+ globals->status |= DBGP_EP_BUSY;
+ pipe->status |= DBGP_EP_BUSY;
+ return 1;
+}
+
+static void dbgp_put(struct dbgp_pipe *pipe)
+{
+ struct dbgp_pipe *globals = &dbgp_ehci_info()->ep_pipe[DBGP_SETUP_EP0];
+ globals->status &= ~DBGP_EP_BUSY;
+ pipe->status &= ~DBGP_EP_BUSY;
+}
+
void usbdebug_tx_byte(struct dbgp_pipe *pipe, unsigned char data)
{
- if (dbgp_ep_is_active(pipe)) {
- pipe->buf[pipe->bufidx++] = data;
- if (pipe->bufidx >= 8) {
- dbgp_bulk_write_x(pipe, pipe->buf, pipe->bufidx);
- pipe->bufidx = 0;
- }
+ if (!dbgp_try_get(pipe))
+ return;
+ pipe->buf[pipe->bufidx++] = data;
+ if (pipe->bufidx >= 8) {
+ dbgp_bulk_write_x(pipe, pipe->buf, pipe->bufidx);
+ pipe->bufidx = 0;
}
+ dbgp_put(pipe);
}
void usbdebug_tx_flush(struct dbgp_pipe *pipe)
{
- if (dbgp_ep_is_active(pipe) && pipe->bufidx > 0) {
+ if (!dbgp_try_get(pipe))
+ return;
+ if (pipe->bufidx > 0) {
dbgp_bulk_write_x(pipe, pipe->buf, pipe->bufidx);
pipe->bufidx = 0;
}
+ dbgp_put(pipe);
}
#if !defined(__PRE_RAM__) && !defined(__SMM__)