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From: Saravana Kannan <saravanak@google.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>
Cc: Saravana Kannan <saravanak@google.com>,
	kernel-team@android.com, linux-kernel@vger.kernel.org,
	Jisheng Zhang <Jisheng.Zhang@synaptics.com>,
	Kevin Hilman <khilman@baylibre.com>,
	John Stultz <john.stultz@linaro.org>,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
	Marc Zyngier <maz@kernel.org>
Subject: [PATCH v1 1/5] driver core: Add debug logs for device link related probe deferrals
Date: Thu, 17 Dec 2020 19:16:59 -0800
Message-ID: <20201218031703.3053753-2-saravanak@google.com> (raw)
In-Reply-To: <20201218031703.3053753-1-saravanak@google.com>

There's insufficient logging when device links or fw_devlink (waiting to
create device links) cause probe deferrals.  This makes it hard to debug
devices not getting probed. So, add debug logs to make it easy to debug.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/core.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 25e08e5f40bd..fe8601197b84 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -929,6 +929,10 @@ int device_links_check_suppliers(struct device *dev)
 	mutex_lock(&fwnode_link_lock);
 	if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
 	    !fw_devlink_is_permissive()) {
+		dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
+			list_first_entry(&dev->fwnode->suppliers,
+			struct fwnode_link,
+			c_hook)->supplier);
 		mutex_unlock(&fwnode_link_lock);
 		return -EPROBE_DEFER;
 	}
@@ -943,6 +947,8 @@ int device_links_check_suppliers(struct device *dev)
 		if (link->status != DL_STATE_AVAILABLE &&
 		    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
 			device_links_missing_supplier(dev);
+			dev_dbg(dev, "probe deferral - supplier %s not ready\n",
+				dev_name(link->supplier));
 			ret = -EPROBE_DEFER;
 			break;
 		}
-- 
2.29.2.684.gfbc64c5ab5-goog


  reply index

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-18  3:16 [PATCH v1 0/5] Enable fw_devlink=on by default Saravana Kannan
2020-12-18  3:16 ` Saravana Kannan [this message]
2020-12-18  3:17 ` [PATCH v1 2/5] driver core: Add device link support for INFERRED flag Saravana Kannan
2020-12-18  3:17 ` [PATCH v1 3/5] driver core: Have fw_devlink use DL_FLAG_INFERRED Saravana Kannan
2020-12-18  3:17 ` [PATCH v1 4/5] driver core: Handle cycles in device links created by fw_devlink Saravana Kannan
2020-12-18  6:39   ` kernel test robot
2020-12-18  6:39   ` [RFC PATCH] driver core: fw_devlink_relax_cycle() can be static kernel test robot
2020-12-18  6:48   ` [PATCH v1 4/5] driver core: Handle cycles in device links created by fw_devlink kernel test robot
2020-12-18  7:12   ` kernel test robot
2020-12-18  3:17 ` [PATCH v1 5/5] driver core: Set fw_devlink=on by default Saravana Kannan
     [not found]   ` <CGME20210111111245eucas1p15acde7ecc2ca7f7782beb8ed74c72022@eucas1p1.samsung.com>
2021-01-11 11:12     ` Marek Szyprowski
     [not found]       ` <CGME20210111141814eucas1p1f388df07b789693a999042b27f0d8c2a@eucas1p1.samsung.com>
2021-01-11 14:18         ` Marek Szyprowski
2021-01-11 21:47           ` Saravana Kannan
2021-01-12  7:11             ` Marek Szyprowski
2021-01-12 20:51               ` Saravana Kannan
2021-01-13  7:04                 ` Marek Szyprowski
2021-01-13 19:23                   ` Saravana Kannan
2021-01-14  7:36                     ` Marek Szyprowski
2021-01-14 18:08                       ` Saravana Kannan
2021-01-18 17:43                 ` Geert Uytterhoeven
2021-01-17 23:01   ` Michael Walle
2021-01-18 21:01     ` Saravana Kannan
2021-01-19 10:41       ` Michael Walle
2021-01-20  0:00         ` Saravana Kannan
2021-01-18 17:39   ` Geert Uytterhoeven
2021-01-18 17:59     ` Marc Zyngier
2021-01-18 19:16       ` Geert Uytterhoeven
2021-01-18 19:30         ` Marc Zyngier
2021-01-18 21:18         ` Saravana Kannan
2021-01-19  9:05           ` Geert Uytterhoeven
2021-01-19 18:08             ` Saravana Kannan
2021-01-19 21:50               ` Saravana Kannan
2021-01-20  9:40                 ` Geert Uytterhoeven
2021-01-20 14:26                   ` Geert Uytterhoeven
2021-01-20 17:22                     ` Saravana Kannan
2021-01-21 16:04                       ` Geert Uytterhoeven
2021-01-25 23:30                         ` Saravana Kannan
2021-01-26  8:25                           ` Geert Uytterhoeven
2021-01-20  9:11               ` Geert Uytterhoeven
2021-01-21  8:22   ` [TEST PATCH v1] driver: core: Make fw_devlink=on more forgiving Saravana Kannan
2021-01-21  8:27     ` Saravana Kannan
2021-01-21 10:37       ` Geert Uytterhoeven
2021-01-22  1:07         ` Saravana Kannan
2021-01-21 10:33     ` Marek Szyprowski
2021-01-25 17:05   ` [PATCH v1 5/5] driver core: Set fw_devlink=on by default Tudor.Ambarus
2021-01-25 18:16     ` Saravana Kannan
2021-01-28 10:59       ` Tudor.Ambarus
2021-01-28 17:04         ` Saravana Kannan
2021-02-10  5:54   ` Guenter Roeck
2021-02-10  8:20     ` Saravana Kannan
2021-02-10 15:10       ` Guenter Roeck
2021-02-10 20:52         ` Saravana Kannan
2021-02-10 21:21           ` Guenter Roeck
2021-02-17  2:39             ` Saravana Kannan
2021-02-17  3:05               ` Guenter Roeck
2021-02-17  3:13                 ` Saravana Kannan
2020-12-18 21:11 ` [PATCH v1 0/5] Enable " Saravana Kannan
2020-12-21  8:18 ` Jisheng Zhang
     [not found]   ` <CAHp75VfqL1QuvjCZ7p23e_2qhY3DUgVNaS--Uk1mEoEHsD8GBA@mail.gmail.com>
2021-01-14 16:49     ` Saravana Kannan
2020-12-21  9:48 ` Rafael J. Wysocki
2021-01-07 20:05 ` Greg Kroah-Hartman
2021-01-07 21:53   ` Saravana Kannan
2021-01-13 11:11   ` Marc Zyngier
2021-01-13 15:27     ` Jon Hunter
2021-01-13 21:29       ` Saravana Kannan
2021-01-14 11:34         ` Jon Hunter
2021-01-14 16:40           ` Saravana Kannan
2021-01-14 16:47             ` Jon Hunter
2021-01-14 16:52               ` Saravana Kannan
2021-01-14 18:55                 ` Jon Hunter
2021-01-14 21:50                   ` Saravana Kannan
2021-01-15 16:12                     ` Jon Hunter
2021-01-15 17:44                       ` Saravana Kannan
2021-01-13 20:56     ` Saravana Kannan
2021-01-13 11:30 ` Jon Hunter
2021-01-13 21:26   ` Saravana Kannan
2021-01-14 16:11     ` Jon Hunter
2021-01-14 16:47       ` Saravana Kannan
2021-01-14 16:56         ` Jon Hunter
2021-01-28 15:03           ` Jon Hunter
2021-01-28 17:27             ` Saravana Kannan
2021-02-11  0:02             ` Saravana Kannan
2021-02-11 15:03               ` Rafael J. Wysocki
2021-02-11 17:14                 ` Saravana Kannan
2021-02-11 17:48                   ` Rafael J. Wysocki
2021-02-12  3:04                     ` Saravana Kannan
2021-01-13 11:44 ` Nicolas Saenz Julienne
2021-01-13 11:48   ` Marc Zyngier
2021-01-13 21:27     ` Saravana Kannan

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