On 10/24/18, Boris Brezillon [off-list ref] wrote:

Hi Arnd,

On Mon, 22 Oct 2018 15:34:01 +0200
Boris Brezillon [off-list ref] wrote:

quoted

+
+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);
	}

Could we maybe mandate that the buffer itself must be aligned here?
What would be a reason why we see an unaligned target buffer?

The open-coded loop should generally work (maybe a little slower),
but it does seem error-prone to use __raw_readl() in general.

      Arnd