From: Srinivas Kandagatla Date: Mon, 7 Mar 2016 02:46:40 +0000 (+0000) Subject: tty: msm_serial: remove static clk rate setting in probe X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=79c9473f115f99906b6ae443708b8ece480e2e88;p=deliverable%2Flinux.git tty: msm_serial: remove static clk rate setting in probe The issue with setting up a fixed clock rate at probe is that it would overwrite the console rate set by the bootloader for its console device. This would result in serial out corruption or missing log when we system is booted with earlycon. This is not a issue if we boot system without earlycon. This setup is at least not required with the mainline driver, this code used to be required because the clk_enable() call would fail if clk_set_rate() wasn't called first. Originally the issue was noticed on DB410c which is based on APQ8016 chipset. Without this patch the console log with earlycon would look like: ... [ 0.000000] RCU: Adjusting geometry for rcu_fanout_leaf=64, nr_cpu_ids=1 [ 0.000000] NR_IRQS:64 nr_irqs:64 0 ����+HH��0.699378] console [ttyMSM0] enabled [ 0.699378] console [ttyMSM0] enabled [ 0.702003] bootconsole [uart0] disabled [ 0.702003] bootconsole [uart0] disabled ... with this patch I can see all the skipped lines on the console Reviewed-by: Stephen Boyd Signed-off-by: Srinivas Kandagatla Acked-by: Andy Gross Tested-by: Pramod Gurav Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 96d3ce8dc2dc..074c797d13af 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -1577,8 +1577,6 @@ static int msm_serial_probe(struct platform_device *pdev) msm_port->pclk = devm_clk_get(&pdev->dev, "iface"); if (IS_ERR(msm_port->pclk)) return PTR_ERR(msm_port->pclk); - - clk_set_rate(msm_port->clk, 1843200); } port->uartclk = clk_get_rate(msm_port->clk);