Re: [PATCH v3 10/15] serial: stm32-usart: Add STM32 USART Driver

From: Russell King - ARM Linux
Date: Thu Mar 26 2015 - 11:47:21 EST


On Tue, Mar 24, 2015 at 02:23:38PM -0400, Peter Hurley wrote:
> Hi Maxime,
>
> On 03/12/2015 05:55 PM, Maxime Coquelin wrote:
> > +static unsigned int stm32_get_mctrl(struct uart_port *port)
> > +{
> > + /*
> > + * This routine is used for geting signals of: DTR, DCD, DSR, RI,
> > + * and CTS/RTS

It's also worth noting that this comment is wrong. This is used to get
the state of DCD, DSR, RI and CTS. DTR and RTS are *not* included
because the core tracks their state.

...

> > + stm32port->clk = devm_clk_get(&pdev->dev, NULL);
> > +
> > + if (WARN_ON(IS_ERR(stm32port->clk)))
>
> Do you really need a stack trace here? Could this be dev_err() instead?
>
> > + return -EINVAL;

Also, propagate the error code.

> > +
> > + /* ensure that clk rate is correct by enabling the clk */
> > + clk_prepare_enable(stm32port->clk);

And remember to check the return value of clk_prepare_enable().

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