[ARM] clkdev: fix clock matching (409dc360) · Commits · 戴 / test

The old matching algorithm was too fuzzy, causing false positives. For example, when asked for device D connection C1 and we only find device D connection C2, we return that as a valid match despite the connection names being different. Change the algorithm such that: An entry with a NULL ID is assumed to be a wildcard. If an entry has a device ID, it must match If an entry has a connection ID, it must match However, we maintain the order of precidence while still only doing a single pass over all entries: dev+con > dev only > con only. Signed-off-by:

Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/clkdev.c

+19 −6

Original line number	Diff line number	Diff line
		@@ -24,6 +24,15 @@
		static LIST_HEAD(clocks);
		static DEFINE_MUTEX(clocks_mutex);

		/*
		* Find the correct struct clk for the device and connection ID.
		* We do slightly fuzzy matching here:
		* An entry with a NULL ID is assumed to be a wildcard.
		* If an entry has a device ID, it must match
		* If an entry has a connection ID, it must match
		* Then we take the most specific entry - with the following
		* order of precidence: dev+con > dev only > con only.
		*/
		static struct clk clk_find(const char dev_id, const char *con_id)
		{
		struct clk_lookup *p;
		@@ -31,13 +40,17 @@ static struct clk clk_find(const char dev_id, const char *con_id)
		int match, best = 0;

		list_for_each_entry(p, &clocks, node) {
		if ((p->dev_id && !dev_id) \|\| (p->con_id && !con_id))
		continue;
		match = 0;
		if (p->dev_id)
		match += 2 * (strcmp(p->dev_id, dev_id) == 0);
		if (p->con_id)
		match += 1 * (strcmp(p->con_id, con_id) == 0);
		if (p->dev_id) {
		if (!dev_id \|\| strcmp(p->dev_id, dev_id))
		continue;
		match += 2;
		}
		if (p->con_id) {
		if (!con_id \|\| strcmp(p->con_id, con_id))
		continue;
		match += 1;
		}
		if (match == 0)
		continue;

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