[PATCH] platform: cros_ec_debugfs: control uptime information request

[Gwendal Grignou]

When EC does not support uptime command (EC_CMD_GET_UPTIME_INFO),
return -EPROTO to read of /sys/kernel/debug/cros_ec/uptime without
calling the EC after the first try.

The EC console log will not contain EC_CMD_GET_UPTIME_INFO anymore.

Signed-off-by: Gwendal Grignou <gwen...@chromium.org>
---
 drivers/platform/chrome/cros_ec_debugfs.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_debugfs.c 
b/drivers/platform/chrome/cros_ec_debugfs.c
index 6ae484989d1f5..70a29afb6d9e7 100644
--- a/drivers/platform/chrome/cros_ec_debugfs.c
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -49,6 +49,8 @@ struct cros_ec_debugfs {
        struct delayed_work log_poll_work;
        /* EC panicinfo */
        struct debugfs_blob_wrapper panicinfo_blob;
+       /* EC uptime */
+       bool uptime_supported;
 };
 
 /*
@@ -256,12 +258,19 @@ static ssize_t cros_ec_uptime_read(struct file *file, 
char __user *user_buf,
        char read_buf[32];
        int ret;
 
+       if (!debug_info->uptime_supported)
+               return -EPROTO;
+
        resp = (struct ec_response_uptime_info *)&msg.resp;
 
        msg.cmd.command = EC_CMD_GET_UPTIME_INFO;
        msg.cmd.insize = sizeof(*resp);
 
        ret = cros_ec_cmd_xfer_status(ec_dev, &msg.cmd);
+       if (ret == -EPROTO && msg.cmd.result == EC_RES_INVALID_COMMAND) {
+               debug_info->uptime_supported = false;
+               return ret;
+       }
        if (ret < 0)
                return ret;
 
@@ -434,6 +443,9 @@ static int cros_ec_debugfs_probe(struct platform_device *pd)
        debug_info->ec = ec;
        debug_info->dir = debugfs_create_dir(name, NULL);
 
+       /* Give uptime a chance to run. */
+       debug_info->uptime_supported = true;
+
        ret = cros_ec_create_panicinfo(debug_info);
        if (ret)
                goto remove_debugfs;
-- 
2.26.2.761.g0e0b3e54be-goog