Change in coreboot[master]: cros-ec: Avoid infinitely looping in google_chromeec_pd_get_amode

[Daisuke Nojiri (Code Review)]

Daisuke Nojiri has uploaded this change for review. ( https://review.coreboot.org/25878

Change subject: cros-ec: Avoid infinitely looping in google_chromeec_pd_get_amode
......................................................................

cros-ec: Avoid infinitely looping in google_chromeec_pd_get_amode

Currently, google_chromeec_pd_get_amode infinitely loops if a TCPC port
is connected to a device with alternate mode(s) and the call is made for
the mode with the index higher than 0 (e.g. Zinger).

This patch adds delay between calls to the EC to query alternate mode
information. This allows the EC to process each call properly.
It also resets all the fields of chromeec_command in each iteration in
case google_chromeec_command changes them.

BUG=b:78630899
BRANCH=none
TEST=Verify Fizz boots without monitors on Zinger. Verify the svid
enumeration happens as expected.

Change-Id: I388ed4bdfac9176d8e690c429e99674ed267004f
Signed-off-by: Daisuke Nojiri 
---
M src/ec/google/chromeec/ec.c
1 file changed, 16 insertions(+), 11 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/78/25878/1

diff --git a/src/ec/google/chromeec/ec.c b/src/ec/google/chromeec/ec.c
index fb3ffab..9676f2d 100644
--- a/src/ec/google/chromeec/ec.c
+++ b/src/ec/google/chromeec/ec.c
@@ -963,23 +963,28 @@
    for (i = 0; i < r.num_ports; i++) {
    	struct ec_params_usb_pd_get_mode_request p;
    	struct ec_params_usb_pd_get_mode_response res;
-
-		p.port = i;
-		p.svid_idx = 0;
-		cmd.cmd_code = EC_CMD_USB_PD_GET_AMODE;
-		cmd.cmd_version = 0;
-		cmd.cmd_data_in = &p;
-		cmd.cmd_size_in = sizeof(p);
-		cmd.cmd_data_out = &res;
-		cmd.cmd_size_out = sizeof(res);
-		cmd.cmd_dev_index = 0;
+		int svid_idx = 0;

do {
+			/* Reset cmd in each iteration in case
+			 * google_chromeec_command changes it. */
+			p.port = i;
+			p.svid_idx = svid_idx;
+			cmd.cmd_code = EC_CMD_USB_PD_GET_AMODE;
+			cmd.cmd_version = 0;
+			cmd.cmd_data_in = &p;
+			cmd.cmd_size_in = sizeof(p);
+			cmd.cmd_data_out = &res;
+			cmd.cmd_size_out = sizeof(res);
+			cmd.cmd_dev_index = 0;
+
    		if (google_chromeec_command(&cmd) < 0)
    			return -1;
    		if (res.svid == svid)
    			return 1;
-			p.svid_idx++;
+			svid_idx++;
+			/* Avoid storming EC */
+			mdelay(100);
    	} while (res.svid);
    }