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From: Christian Marangi <ansuelsmth@gmail.com>
To: Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Christian Marangi <ansuelsmth@gmail.com>
Subject: [PATCH v2 1/2] clk: Warn and add workaround on misuse of .parent_data with .name only
Date: Tue, 31 Jan 2023 17:08:28 +0100	[thread overview]
Message-ID: <20230131160829.23369-1-ansuelsmth@gmail.com> (raw)

By a simple mistake in a .parent_names to .parent_data conversion it was
found that clk core assume fw_name is always provided with a parent_data
struct for each parent and never fallback to .name to get parent name even
if declared.

This is caused by clk_core_get that only checks for parent .fw_name and
doesn't handle .name.

While it's sane to request the dev to correctly do the conversion and
add both .fw_name and .name in a parent_data struct, it's not sane to
silently drop parents without a warning.

Fix this in 2 ways. Add a kernel warning when a wrong implementation is
used and copy .name in .fw_name in parent map populate function to
handle clk problems and malfunctions.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/clk/clk.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 57b83665e5c3..dccd4ea6f692 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -4015,10 +4015,21 @@ static int clk_core_populate_parent_map(struct clk_core *core,
 			ret = clk_cpy_name(&parent->name, parent_names[i],
 					   true);
 		} else if (parent_data) {
+			const char *parent_name;
+
 			parent->hw = parent_data[i].hw;
 			parent->index = parent_data[i].index;
+			parent_name = parent_data[i].fw_name;
+
+			if (!parent_name && parent_data[i].name) {
+				WARN(1, "Empty .fw_name with .name in %s's .parent_data. Using .name for .fw_name declaration.\n",
+				     core->name);
+				parent_name = parent_data[i].name;
+			}
+
 			ret = clk_cpy_name(&parent->fw_name,
-					   parent_data[i].fw_name, false);
+					   parent_name, false);
+
 			if (!ret)
 				ret = clk_cpy_name(&parent->name,
 						   parent_data[i].name,
-- 
2.38.1


             reply	other threads:[~2023-01-31 16:08 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-31 16:08 Christian Marangi [this message]
2023-01-31 16:08 ` [PATCH v2 2/2] clk: gate: Add missing fw_name for clk_gate_register_test_parent_data_legacy Christian Marangi
2023-02-11  0:52   ` Stephen Boyd
2023-02-10 18:39     ` Christian Marangi
2023-02-11  0:40 ` [PATCH v2 1/2] clk: Warn and add workaround on misuse of .parent_data with .name only Stephen Boyd
2023-02-10 18:34   ` Christian Marangi
2023-02-15 18:54     ` Stephen Boyd
2023-02-15 23:33       ` Christian Marangi

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