On Tue, Oct 06, 2015 at 04:01:32PM +0200, Jiri Prchal wrote:
> This patch adds functionality for Cypress FRAMs on SPI bus, such as FM25V05,
> FM25V10 etc.

I'm not entirely sure why I got CCed on this?

> +	mutex_lock(&at25->lock);
> +
> +	status = spi_sync(at25->spi, &m);
> +	dev_dbg(&at25->spi->dev,
> +		"read %Zd bytes of ID --> %d\n",
> +	 FM25_ID_LEN, (int) status);
> +
> +	mutex_unlock(&at25->lock);

There is no point in holding a lock around spi_sync(), the SPI framework
has locking which will ensure spi_sync() and spi_async() calls will be
serialised.