Re: [PATCH v2 1/2] tty: serial: 8250_mtk: enable baud clock
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: 2025-09-15 13:41:28
Also in:
linux-mediatek, linux-serial, lkml
Il 15/09/25 15:06, Daniel Golle ha scritto:
Some MediaTek SoCs got a gated UART baud clock, which currently gets
disabled as the clk subsystem believes it would be unused. This results in
the uart freezing right after "clk: Disabling unused clocks" on those
platforms.
To fix this request the baud clock to be prepared and enabled during probe.
Fixes: e32a83c70cf9 ("serial: 8250-mtk: modify mtk uart power and clock management")
Suggested-by: Sam Shih <redacted>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>Thanks for caring about power management. However, this and the addition in PM ops should be a single commit. It's even using the same Fixes tag...! :-) I've read both of the commits in this series and the code LGTM. tty: serial: 8250_mtk: Enable baud clock and manage in runtime PM Please, squash the two commits, after which... Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cheers, Angelo
quoted hunk ↗ jump to hunk
--- v2: no changes drivers/tty/serial/8250/8250_mtk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index b44de2ed7413..9329ed1f759d 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c@@ -475,13 +475,13 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, int dmacnt; #endif - data->uart_clk = devm_clk_get(&pdev->dev, "baud"); + data->uart_clk = devm_clk_get_enabled(&pdev->dev, "baud"); if (IS_ERR(data->uart_clk)) { /* * For compatibility with older device trees try unnamed * clk when no baud clk can be found. */ - data->uart_clk = devm_clk_get(&pdev->dev, NULL); + data->uart_clk = devm_clk_get_enabled(&pdev->dev, NULL); if (IS_ERR(data->uart_clk)) { dev_warn(&pdev->dev, "Can't get uart clock\n"); return PTR_ERR(data->uart_clk);