diff mbox series

[v2,05/12] cxl/acpi: Improve debug messages in cxl_acpi_probe()

Message ID 20221018132341.76259-6-rrichter@amd.com
State New
Headers
Series cxl: Add support for Restricted CXL hosts (RCD mode) |

Commit Message

Robert Richter Oct. 18, 2022, 1:23 p.m. UTC 
  In cxl_acpi_probe() the iterator bus_for_each_dev() walks through all
CXL hosts. Since all dev_*() debug messages point to the ACPI0017
device which is the CXL root for all hosts, the device information is
pointless as it is always the same device. Change this to use the host
device for this instead.

Also, add additional host specific information such as CXL support,
UID and CHBCR.

This is an example log:

 acpi ACPI0016:00: UID found: 4
 acpi ACPI0016:00: CHBCR found: 0x28090000000
 acpi ACPI0016:00: dport added to root0
 acpi ACPI0016:00: host-bridge: ACPI0016:00
  pci0000:7f: host supports CXL

Signed-off-by: Robert Richter <rrichter@amd.com>
---
 drivers/cxl/acpi.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Comments

Dan Williams Oct. 21, 2022, 1 a.m. UTC | #1 
Robert Richter wrote:
> In cxl_acpi_probe() the iterator bus_for_each_dev() walks through all
> CXL hosts. Since all dev_*() debug messages point to the ACPI0017
> device which is the CXL root for all hosts, the device information is
> pointless as it is always the same device. Change this to use the host
> device for this instead.
> 
> Also, add additional host specific information such as CXL support,
> UID and CHBCR.
> 
> This is an example log:
> 
>  acpi ACPI0016:00: UID found: 4
>  acpi ACPI0016:00: CHBCR found: 0x28090000000
>  acpi ACPI0016:00: dport added to root0
>  acpi ACPI0016:00: host-bridge: ACPI0016:00
>   pci0000:7f: host supports CXL
> 
> Signed-off-by: Robert Richter <rrichter@amd.com>
> ---
>  drivers/cxl/acpi.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
> index 31e104f0210f..fb9f72813067 100644
> --- a/drivers/cxl/acpi.c
> +++ b/drivers/cxl/acpi.c
> @@ -221,6 +221,8 @@ static int add_host_bridge_uport(struct device *match, void *arg)
>  	if (IS_ERR(port))
>  		return PTR_ERR(port);
>  
> +	dev_info(pci_root->bus->bridge, "host supports CXL\n");
> +

I generally advocate for drivers to be silent, but this is a fundamental
message in a place that is helpful to indicate whether platform-firmware
is doing its job correctly, and it's only once per host bridge.

Applied for v6.2.
diff mbox series

Patch

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 31e104f0210f..fb9f72813067 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -221,6 +221,8 @@  static int add_host_bridge_uport(struct device *match, void *arg)
 	if (IS_ERR(port))
 		return PTR_ERR(port);
 
+	dev_info(pci_root->bus->bridge, "host supports CXL\n");
+
 	return 0;
 }
 
@@ -264,11 +266,12 @@  static int add_host_bridge_dport(struct device *match, void *arg)
 	status = acpi_evaluate_integer(bridge->handle, METHOD_NAME__UID, NULL,
 				       &uid);
 	if (status != AE_OK) {
-		dev_err(host, "unable to retrieve _UID of %s\n",
-			dev_name(match));
+		dev_err(match, "unable to retrieve _UID\n");
 		return -ENODEV;
 	}
 
+	dev_dbg(match, "UID found: %lld\n", uid);
+
 	ctx = (struct cxl_chbs_context) {
 		.dev = host,
 		.uid = uid,
@@ -276,11 +279,12 @@  static int add_host_bridge_dport(struct device *match, void *arg)
 	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx);
 
 	if (ctx.chbcr == 0) {
-		dev_warn(host, "No CHBS found for Host Bridge: %s\n",
-			 dev_name(match));
+		dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n", uid);
 		return 0;
 	}
 
+	dev_dbg(match, "CHBCR found: 0x%08llx\n", (u64)ctx.chbcr);
+
 	dport = devm_cxl_add_dport(root_port, match, uid, ctx.chbcr);
 	if (IS_ERR(dport))
 		return PTR_ERR(dport);