serial: imx: remove unbalanced clk_prepare (9e7b399d) · Commits · 戴 / test

The current code attempts to prepare clk_per and clk_ipg before using the device. However, the result is an extra prepare call on each clock. Here is the output of uart clocks (only uart enabled and used as console): $ grep uart /sys/kernel/debug/clk/clk_summary uart_serial 1 2 80000000 0 0 uart 1 2 66000000 0 0 This patch balances the calls of prepares. The result is: $ grep uart /sys/kernel/debug/clk/clk_summary uart_serial 1 1 80000000 0 0 uart 1 1 66000000 0 0 Cc: Fabio Estevam <festevam@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: linux-serial@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by:

Eduardo Valentin <edubezval@gmail.com> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/imx.c

+6 −14

Original line number	Diff line number	Diff line
		@@ -1630,12 +1630,12 @@ imx_console_write(struct console co, const char s, unsigned int count)
		int locked = 1;
		int retval;

		retval = clk_enable(sport->clk_per);
		retval = clk_prepare_enable(sport->clk_per);
		if (retval)
		return;
		retval = clk_enable(sport->clk_ipg);
		retval = clk_prepare_enable(sport->clk_ipg);
		if (retval) {
		clk_disable(sport->clk_per);
		clk_disable_unprepare(sport->clk_per);
		return;
		}

		@@ -1674,8 +1674,8 @@ imx_console_write(struct console co, const char s, unsigned int count)
		if (locked)
		spin_unlock_irqrestore(&sport->port.lock, flags);

		clk_disable(sport->clk_ipg);
		clk_disable(sport->clk_per);
		clk_disable_unprepare(sport->clk_ipg);
		clk_disable_unprepare(sport->clk_per);
		}

		/*
		@@ -1776,14 +1776,6 @@ imx_console_setup(struct console co, char options)

		retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);

		clk_disable(sport->clk_ipg);
		if (retval) {
		clk_unprepare(sport->clk_ipg);
		goto error_console;
		}

		retval = clk_prepare(sport->clk_per);
		if (retval)
		clk_disable_unprepare(sport->clk_ipg);

		error_console:

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