Re: [PATCH v9 6/9] i3c: master: Add driver for Cadence IP

[Boris Brezillon <boris.brezillon@bootlin.com>]

Hi Arnd,

On Mon, 22 Oct 2018 15:34:01 +0200
Boris Brezillon <boris.brezillon@bootlin.com> wrote:


> +
> +static void cdns_i3c_master_rd_from_rx_fifo(struct cdns_i3c_master *master,
> +					    u8 *bytes, int nbytes)
> +{
> +	readsl(master->regs + RX_FIFO, bytes, nbytes / 4);

Vitor reported a problem with readsl(): this function expects the 2nd
argument to be aligned on 32-bit, which is not guaranteed here. Unless
you see a better solution, I'll switch back to a loop doing:

	for (i = 0; i < nbytes; i += 4) {
		u32 tmp = __raw_readl(...);
		memcpy(bytes + i, &tmp,
		       nbytes - i  > 4 ? 4 : nbytes - i);
	}

> +	if (nbytes & 3) {
> +		u32 tmp;
> +
> +		readsl(master->regs + RX_FIFO, &tmp, 1);
> +		memcpy(bytes + (nbytes & ~3), &tmp, nbytes & 3);
> +	}
> +}

Regards,

Boris