[4.19,245/422] serial: samsung: Enable baud clock for UART reset procedure in resume

Message ID 20191119051414.877369929@linuxfoundation.org
State New
Headers show
Series
  • Untitled series #25072
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Commit Message

Greg Kroah-Hartman Nov. 19, 2019, 5:17 a.m.
From: Marek Szyprowski <m.szyprowski@samsung.com>


[ Upstream commit 1ff3652bc7111df26b5807037f624be294cf69d5 ]

Ensure that the baud clock is also enabled for UART register writes in
driver resume. On Exynos5433 SoC this is needed to avoid external abort
issue.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Sasha Levin <sashal@kernel.org>

---
 drivers/tty/serial/samsung.c | 8 ++++++++
 1 file changed, 8 insertions(+)

-- 
2.20.1

Patch

diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index c6058b52d5d59..2a49b6d876b87 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1944,7 +1944,11 @@  static int s3c24xx_serial_resume(struct device *dev)
 
 	if (port) {
 		clk_prepare_enable(ourport->clk);
+		if (!IS_ERR(ourport->baudclk))
+			clk_prepare_enable(ourport->baudclk);
 		s3c24xx_serial_resetport(port, s3c24xx_port_to_cfg(port));
+		if (!IS_ERR(ourport->baudclk))
+			clk_disable_unprepare(ourport->baudclk);
 		clk_disable_unprepare(ourport->clk);
 
 		uart_resume_port(&s3c24xx_uart_drv, port);
@@ -1967,7 +1971,11 @@  static int s3c24xx_serial_resume_noirq(struct device *dev)
 			if (rx_enabled(port))
 				uintm &= ~S3C64XX_UINTM_RXD_MSK;
 			clk_prepare_enable(ourport->clk);
+			if (!IS_ERR(ourport->baudclk))
+				clk_prepare_enable(ourport->baudclk);
 			wr_regl(port, S3C64XX_UINTM, uintm);
+			if (!IS_ERR(ourport->baudclk))
+				clk_disable_unprepare(ourport->baudclk);
 			clk_disable_unprepare(ourport->clk);
 		}
 	}