Re: [PATCH 06/23] cxl/pci: Don't check media status for mbox access

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Fri, 19 Nov 2021 16:02:33 -0800
Ben Widawsky <ben.widawsky@intel.com> wrote:

> Media status is necessary for using HDM contained in a CXL device but is
> not needed for mailbox accesses. Therefore remove this check. It will be
> necessary to have this check (in a different place) when enabling HDM.
> 
> Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>

One could perhaps argue this was a bug, but it was hopefully harmless on real devices.
Out of curiosity, did you find a clear definition of what 'User data' includes?
Obviously includes any data in the HDM region, but what about region meta data?

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> This patch did not exist in RFCv2
> ---
>  drivers/cxl/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index 869b4fc18e27..711bf4514480 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -230,7 +230,7 @@ static int cxl_pci_mbox_get(struct cxl_dev_state *cxlds)
>  	 * but it's possible early devices implemented this before the ECN.
>  	 */
>  	md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
> -	if (!(md_status & CXLMDEV_MBOX_IF_READY && CXLMDEV_READY(md_status))) {
> +	if (!(md_status & CXLMDEV_MBOX_IF_READY)) {
>  		dev_err(dev, "mbox: reported doorbell ready, but not mbox ready\n");
>  		rc = -EBUSY;
>  		goto out;