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Date:   Thu, 13 Jan 2022 14:16:03 +0800
Message-Id: <20220113141533.Bluez.1.Iad485a29772515142eefb1b120d5eb5e101d82f6@changeid>
Mime-Version: 1.0
Subject: [Bluez PATCH] device: Fix device can't be scanned for 5 mins after reboot
From:   Archie Pusaka <apusaka@google.com>
To:     linux-bluetooth <linux-bluetooth@vger.kernel.org>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     CrosBT Upstreaming <chromeos-bluetooth-upstreaming@chromium.org>,
        Archie Pusaka <apusaka@chromium.org>,
        Shuo-Peng Liao <deanliao@chromium.org>
Content-Type: text/plain; charset="UTF-8"
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From: Archie Pusaka <apusaka@chromium.org>

After the patches which limit the attempts of doing remote name
resolving, there's an issue which prevents BlueZ to RNR new devices
for 5 minutes after reboot. It's caused by failed_time is init to 0,
and is then treated as the timestamp when the device failed RNR.
However, actually there is no failure yet.

This CL fixes it by always allowing RNR when failed_time = 0.

Reviewed-by: Shuo-Peng Liao <deanliao@chromium.org>
---

 src/device.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/device.c b/src/device.c
index f2447c478e..16b1ed5bd3 100644
--- a/src/device.c
+++ b/src/device.c
@@ -4487,10 +4487,15 @@ bool device_is_name_resolve_allowed(struct btd_device *device)
 
 	clock_gettime(CLOCK_MONOTONIC, &now);
 
-	/* If now < failed_time, it means the clock has somehow turned back,
-	 * possibly because of system restart. Allow name request in this case.
+	/* Allow name request for any of these cases:
+	 * (1) failed_time is empty (0). Meaning no prior failure.
+	 * (2) now < failed_time. Meaning the clock has somehow turned back,
+	 *     possibly because of system restart. Allow just to be safe.
+	 * (3) now >= failed_time + name_request_retry_delay. Meaning the
+	 *     period of not sending name request is over.
 	 */
-	return now.tv_sec < device->name_resolve_failed_time ||
+	return device->name_resolve_failed_time == 0 ||
+		now.tv_sec < device->name_resolve_failed_time ||
 		now.tv_sec >= device->name_resolve_failed_time +
 					btd_opts.name_request_retry_delay;
 }
-- 
2.34.1.575.g55b058a8bb-goog