Re: [PATCH 3/3] spi: switch to devm_spi_alloc_master

[Gerhard Sittig]

On Fri, Jan 31, 2014 at 11:23 +0100, Maxime Ripard wrote:
> 
> Make the existing users of devm_spi_register_master use the
> devm_spi_alloc_master function to avoid leaking memory.
> 
> [ ... ]
>  drivers/spi/spi-mpc512x-psc.c    | 19 ++++++++-----------

Note that the context for the MPC512x SPI driver will change in
3.14-rc1, so you will have to rebase after the merge window.

> diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
> index 46d2313..f376595 100644
> --- a/drivers/spi/spi-mpc512x-psc.c
> +++ b/drivers/spi/spi-mpc512x-psc.c
> @@ -479,7 +479,7 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
>  	char clk_name[16];
>  	struct clk *clk;
>  
> -	master = spi_alloc_master(dev, sizeof *mps);
> +	master = devm_spi_alloc_master(dev, sizeof *mps);
>  	if (master == NULL)
>  		return -ENOMEM;
>  
> @@ -507,8 +507,7 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
>  	tempp = devm_ioremap(dev, regaddr, size);
>  	if (!tempp) {
>  		dev_err(dev, "could not ioremap I/O port range\n");
> -		ret = -EFAULT;
> -		goto free_master;
> +		return -EFAULT;
>  	}
>  	mps->psc = tempp;
>  	mps->fifo =
> @@ -516,19 +515,19 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
>  	ret = devm_request_irq(dev, mps->irq, mpc512x_psc_spi_isr, IRQF_SHARED,
>  				"mpc512x-psc-spi", mps);
>  	if (ret)
> -		goto free_master;
> +		return ret;
>  	init_completion(&mps->txisrdone);
>  
>  	psc_num = master->bus_num;
>  	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
>  	clk = devm_clk_get(dev, clk_name);
> -	if (IS_ERR(clk)) {
> -		ret = PTR_ERR(clk);
> -		goto free_master;
> -	}
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
>  	ret = clk_prepare_enable(clk);
>  	if (ret)
> -		goto free_master;
> +		return ret;
> +
>  	mps->clk_mclk = clk;
>  	mps->mclk_rate = clk_get_rate(clk);
>  
> @@ -544,8 +543,6 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
>  
>  free_clock:
>  	clk_disable_unprepare(mps->clk_mclk);
> -free_master:
> -	spi_master_put(master);
>  
>  	return ret;
>  }

Reading the diff in the SPI master driver, the change appears to
be balanced, and replacing 'goto free_master' with immediate
return looks appropriate.

Can't comment on the correctness of removing the spi_master_put()
call when switching from spi_alloc_master() to
devm_spi_alloc_master().  This gets discussed in the other
subthread, dealing with the generic subsystem approach.


virtually yours
Gerhard Sittig
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