[coreboot-gerrit] New patch to review for coreboot: d6f4454 usbdebug: Adjust endpoint retry timeouts

[Kyösti Mälkki (kyosti.malkki@gmail.com)]

Kyösti Mälkki (kyosti.malkki at gmail.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3882

-gerrit

commit d6f4454a2b6adc98ed45a558a5035abb45469402
Author: Kyösti Mälkki <kyosti.malkki at gmail.com>
Date:   Mon Aug 19 12:45:16 2013 +0300

    usbdebug: Adjust endpoint retry timeouts
    
    Approximate transaction completion timeout in milliseconds instead of
    using a fixed loop count. Timeouts are set to 125ms to approximate the
    old retry count of 1000 microframes.
    
    Change Setup Stage of control messages to have no retries, while data
    and status stages may retry until timing out at 125ms.
    
    Change-Id: I63313f994d0bd3444a3aab527ca942da5de9e6fa
    Signed-off-by: Kyösti Mälkki <kyosti.malkki at gmail.com>
---
 src/lib/usbdebug.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/src/lib/usbdebug.c b/src/lib/usbdebug.c
index 4ff2deb..c42140f 100644
--- a/src/lib/usbdebug.c
+++ b/src/lib/usbdebug.c
@@ -43,6 +43,8 @@ struct dbgp_pipe
 	u8 endpoint;
 	u8 pid;
 	u8 status;
+	int timeout_ms;
+
 	u8 bufidx;
 	char buf[8];
 };
@@ -110,7 +112,6 @@ static int dbgp_enabled(void);
 #define DBGP_MICROFRAME_TIMEOUT_US	1000
 #define DBGP_MICROFRAME_RETRIES		10
 #define DBGP_MAX_PACKET		8
-#define DBGP_LOOPS 1000
 
 static struct ehci_debug_info glob_dbg_info CAR_GLOBAL;
 #if !defined(__PRE_RAM__) && !defined(__SMM__)
@@ -151,14 +152,23 @@ static void dbgp_breath(void)
 }
 
 static int dbgp_wait_until_done(struct ehci_dbg_port *ehci_debug, struct dbgp_pipe *pipe,
-	unsigned ctrl, int loop)
+	unsigned ctrl, int timeout_ms)
 {
 	u32 rd_ctrl, rd_pids;
 	u8 lpid;
 	int ret, host_retries;
+	int loop, max_loop;
 
-retry:
+	/* Estimate that a transaction completes in a one microframe
+	 * time of 125 us.
+	 */
+	max_loop = timeout_ms ? timeout_ms * (1000 / 125) : 1;
+	loop = 0;
+device_retry:
 	host_retries = 0;
+	if (loop++ >= max_loop)
+		return -DBGP_ERR_BAD;
+
 host_retry:
 	if (host_retries++ >= DBGP_MICROFRAME_RETRIES)
 		return -DBGP_ERR_BAD;
@@ -189,16 +199,12 @@ host_retry:
 	 */
 	else if (lpid == USB_PID_NYET) {
 		dbgp_breath();
-		if (--loop > 0)
-			goto retry;
-		ret = -DBGP_ERR_BAD;
+		goto device_retry;
 	}
 
 	/* If I get a NACK or out-of-sync DATA PID, reissue the transmission. */
 	else if ((lpid == USB_PID_NAK) || (lpid == (pipe->pid ^ USB_PID_DATA_TOGGLE))) {
-		if (--loop > 0)
-			goto retry;
-		ret = -DBGP_ERR_BAD;
+		goto device_retry;
 	}
 
 	/* Abort on STALL handshake for endpoint 0.*/
@@ -258,7 +264,7 @@ static int dbgp_bulk_write(struct ehci_dbg_port *ehci_debug, struct dbgp_pipe *p
 	write32((unsigned long)&ehci_debug->address, addr);
 	write32((unsigned long)&ehci_debug->pids, pids);
 
-	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, DBGP_LOOPS);
+	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, pipe->timeout_ms);
 
 	return ret;
 }
@@ -270,7 +276,7 @@ int dbgp_bulk_write_x(struct dbgp_pipe *pipe, const char *bytes, int size)
 }
 
 static int dbgp_bulk_read(struct ehci_dbg_port *ehci_debug, struct dbgp_pipe *pipe,
-	void *data, int size, int loops)
+	void *data, int size)
 {
 	u32 pids, addr, ctrl;
 	int ret;
@@ -287,7 +293,7 @@ static int dbgp_bulk_read(struct ehci_dbg_port *ehci_debug, struct dbgp_pipe *pi
 
 	write32((unsigned long)&ehci_debug->address, addr);
 	write32((unsigned long)&ehci_debug->pids, pids);
-	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, loops);
+	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, pipe->timeout_ms);
 	if (ret < 0)
 		return ret;
 
@@ -300,7 +306,7 @@ static int dbgp_bulk_read(struct ehci_dbg_port *ehci_debug, struct dbgp_pipe *pi
 int dbgp_bulk_read_x(struct dbgp_pipe *pipe, void *data, int size)
 {
 	struct ehci_debug_info *dbg_info = dbgp_ehci_info();
-	return dbgp_bulk_read(dbg_info->ehci_debug, pipe, data, size, DBGP_LOOPS);
+	return dbgp_bulk_read(dbg_info->ehci_debug, pipe, data, size);
 }
 
 static void dbgp_mdelay(int ms)
@@ -337,6 +343,7 @@ static int dbgp_control_msg(struct ehci_dbg_port *ehci_debug, unsigned devnum, i
 	pipe->devnum = devnum;
 	pipe->endpoint = 0;
 	pipe->pid = USB_PID_DATA0;
+	pipe->timeout_ms = 125;
 	addr = DBGP_EPADDR(pipe->devnum, pipe->endpoint);
 	pids = DBGP_PID_SET(pipe->pid, USB_PID_SETUP);
 
@@ -348,13 +355,13 @@ static int dbgp_control_msg(struct ehci_dbg_port *ehci_debug, unsigned devnum, i
 	dbgp_set_data(ehci_debug, &req, sizeof(req));
 	write32((unsigned long)&ehci_debug->address, addr);
 	write32((unsigned long)&ehci_debug->pids, pids);
-	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, DBGP_LOOPS);
+	ret = dbgp_wait_until_done(ehci_debug, pipe, ctrl, 0);
 	if (ret < 0)
 		return ret;
 
 	/* Data stage (optional) */
 	if (read && size)
-		ret = dbgp_bulk_read(ehci_debug, pipe, data, size, DBGP_LOOPS);
+		ret = dbgp_bulk_read(ehci_debug, pipe, data, size);
 	else if (!read && size)
 		ret = dbgp_bulk_write(ehci_debug, pipe, data, size);
 
@@ -371,7 +378,7 @@ static int dbgp_control_msg(struct ehci_dbg_port *ehci_debug, unsigned devnum, i
 	}
 
 	write32((unsigned long)&ehci_debug->pids, pids);
-	ret2 = dbgp_wait_until_done(ehci_debug, pipe, ctrl, DBGP_LOOPS);
+	ret2 = dbgp_wait_until_done(ehci_debug, pipe, ctrl, pipe->timeout_ms);
 	if (ret2 < 0)
 		return ret2;
 
@@ -635,6 +642,7 @@ debug_dev_found:
 	for (i=1; i<DBGP_MAX_ENDPOINTS; i++) {
 		info->ep_pipe[i].devnum = USB_DEBUG_DEVNUM;
 		info->ep_pipe[i].pid = USB_PID_DATA0;
+		info->ep_pipe[i].timeout_ms = 125;
 	}
 	info->ep_pipe[DBGP_CONSOLE_EPOUT].endpoint = dbgp_desc.bDebugOutEndpoint;
 	info->ep_pipe[DBGP_CONSOLE_EPIN].endpoint = dbgp_desc.bDebugInEndpoint;