Re: [PATCH 03/14] cxl/mem: Find device capabilities

[David Rientjes]

On Fri, 29 Jan 2021, Ben Widawsky wrote:

> +static int cxl_mem_setup_mailbox(struct cxl_mem *cxlm)
> +{
> +	const int cap = cxl_read_mbox_reg32(cxlm, CXLDEV_MB_CAPS_OFFSET);
> +
> +	cxlm->mbox.payload_size =
> +		1 << CXL_GET_FIELD(cap, CXLDEV_MB_CAP_PAYLOAD_SIZE);
> +
> +	/* 8.2.8.4.3 */
> +	if (cxlm->mbox.payload_size < 256) {
> +		dev_err(&cxlm->pdev->dev, "Mailbox is too small (%zub)",
> +			cxlm->mbox.payload_size);
> +		return -ENXIO;
> +	}

Any reason not to check cxlm->mbox.payload_size > (1 << 20) as well and 
return ENXIO if true?