Re: [PATCH 1/3] cxl/mem: Quiet port walking warning

[Robert Richter <rric@kernel.org>]

On 16.12.22 17:33:32, Dan Williams wrote:
> The cxl_mem driver attempts to establish, or revalidate, the cxl_port
> hierarcy to attach a cxl_memdev to a CXL platform topology. There is a
> natural race (on ACPI platforms) between when the cxl_mem driver
> attempts to attach and when the cxl_acpi driver establishes the root of
> the topology.
> 
> If cxl_mem_probe() runs first it will iterate to the top of the device
> topology without finding the CXL platform root. That situation is benign
> / expected, so stop warning about it. The cxl_acpi driver will poke
> cxl_mem_probe() to try again once the CXL platform root is established.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/cxl/core/port.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
> index 810e60cc331c..6296d2bc909a 100644
> --- a/drivers/cxl/core/port.c
> +++ b/drivers/cxl/core/port.c
> @@ -1400,8 +1400,8 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd)
>  
>  		uport_dev = dport_dev->parent;
>  		if (!uport_dev) {
> -			dev_warn(dev, "at %s no parent for dport: %s\n",
> -				 dev_name(iter), dev_name(dport_dev));
> +			dev_dbg(dev, "at %s no parent for dport: %s\n",
> +				dev_name(iter), dev_name(dport_dev));
>  			return -ENXIO;

Maybe we should also change the return code to the common -EAGAIN for
this case here too? It looks like it is just passed to
cxl_mem_probe(), so there are probably no side effects of this change.
The probe is triggered then again by the base driver.

-Robert