Re: [PATCH 6/7] cxl/mbox: Shout upon async bgcmd race

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

On Tue, 17 Jun 2025 12:36:10 -0700
Davidlohr Bueso <dave@stgolabs.net> wrote:

> Make the condition a warning, as the mailbox will be corrupted
> on such cases, which may trigger harder to debug issues down the
> line when simply returning a common error.

This is a little confusing.  I assume it is meant to be impossible to hit
this race?
> 
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
> ---
>  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 6ada0f502914..6404b01b64c9 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -326,7 +326,7 @@ static int __cxl_pci_mbox_send_cmd(struct cxl_mailbox *cxl_mbox,
>  		    mbox_cmd->user) {
>  			int timeout;
>  
> -			if (mds->bg.opcode)
> +			if (WARN_ON_ONCE(mds->bg.opcode))
>  				return -EBUSY;
>  
>  			/* give first timeout a second */