Re: [PATCH 2/2] spi: add driver for STM32 SPI controller

[Amelie DELAUNAY]

Hi Mark,

Thanks for your review.

On 06/21/2017 05:13 PM, Mark Brown wrote:
> On Wed, Jun 21, 2017 at 04:32:06PM +0200, Amelie Delaunay wrote:
>
> A few minor stylistic things but overall this looks really nice, please
> send followup patches fixing these style things.
>
> > +	/* Determine the first power of 2 greater than or equal to div */
> > +	mbrdiv = (div & (div - 1)) ? fls(div) : fls(div) - 1;
>
> Please write normal conditional statements, it makes things much easier
> to read.
> OK, I'll fix it in v2.

> > +static bool stm32_spi_can_dma(struct spi_master *master,
> > +			      struct spi_device *spi_dev,
> > +			      struct spi_transfer *transfer)
> > +{
> > +	struct stm32_spi *spi = spi_master_get_devdata(master);
> > +
> > +	dev_dbg(spi->dev, "%s: %s\n", __func__,
> > +		(!!(transfer->len > spi->fifo_size)) ? "true" : "false");
> > +
> > +	return !!(transfer->len > spi->fifo_size);
>
> This !! is redundant, you're converting a boolean value into a boolean
> value.
You're right.

> > +	buswidth = (spi->cur_bpw <= 8) ? DMA_SLAVE_BUSWIDTH_1_BYTE :
> > +		   (spi->cur_bpw <= 16) ? DMA_SLAVE_BUSWIDTH_2_BYTES :
> > +		   DMA_SLAVE_BUSWIDTH_4_BYTES;
> > +
> > +	/* Valid for DMA Half or Full Fifo threshold */
> > +	maxburst = (spi->cur_fthlv == 2) ? 1 : spi->cur_fthlv;
>
> Again, please use normal conditional statements - people have to read
> things.
OK.
> > +static int stm32_spi_suspend(struct device *dev)
> > +{
> > +	struct spi_master *master = dev_get_drvdata(dev);
> > +	struct stm32_spi *spi = spi_master_get_devdata(master);
> > +	int ret;
> > +
> > +	ret = spi_master_suspend(master);
> > +	if (ret)
> > +		return ret;
> > +
> > +	clk_disable_unprepare(spi->clk);
>
> It'd be good to also have the clock disabled by runtime PM, that will
> save a little more power.  There's support for enabling and disabling
> the device in the core so it should just be adding callbacks.  Not
> essential though.
OK I'll have a look.

Regards,
Amelie