Nouveau - Nov 2025 - [PATCH v6 1/4] gpu: nova-core: implement Display for Spec

Implement Display for Spec. This simplifies the dev_info!() code for
printing banners such as:

    NVIDIA (Chipset: GA104, Architecture: Ampere, Revision: a.1)

Cc: Alexandre Courbot <acourbot at nvidia.com>
Cc: Danilo Krummrich <dakr at kernel.org>
Cc: Timur Tabi <ttabi at nvidia.com>
Signed-off-by: John Hubbard <jhubbard at nvidia.com>
---
 drivers/gpu/nova-core/gpu.rs | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index 802e71e4f97d..7fd9e91771a6 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -180,6 +180,18 @@ fn new(bar: &Bar0) -> Result<Spec> {
     }
 }
 
+impl fmt::Display for Spec {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
+        write!(
+            f,
+            "Chipset: {}, Architecture: {:?}, Revision: {}",
+            self.chipset,
+            self.chipset.arch(),
+            self.revision
+        )
+    }
+}
+
 /// Structure holding the resources required to operate the GPU.
 #[pin_data]
 pub(crate) struct Gpu {
@@ -206,13 +218,7 @@ pub(crate) fn new<'a>(
     ) -> impl PinInit<Self, Error> + 'a {
         try_pin_init!(Self {
             spec: Spec::new(bar).inspect(|spec| {
-                dev_info!(
-                    pdev.as_ref(),
-                    "NVIDIA (Chipset: {}, Architecture: {:?}, Revision:
{})\n",
-                    spec.chipset,
-                    spec.chipset.arch(),
-                    spec.revision
-                );
+                dev_info!(pdev.as_ref(),"NVIDIA ({})\n", spec);
             })?,
 
             // We must wait for GFW_BOOT completion before doing any
significant setup on the GPU.
-- 
2.51.2

On Fri, 2025-11-07 at 20:39 -0800, John Hubbard wrote:
> Implement Display for Spec. This simplifies the dev_info!() code for
> printing banners such as:
> 
> ??? NVIDIA (Chipset: GA104, Architecture: Ampere, Revision: a.1)
> 
> Cc: Alexandre Courbot <acourbot at nvidia.com>
> Cc: Danilo Krummrich <dakr at kernel.org>
> Cc: Timur Tabi <ttabi at nvidia.com>
> Signed-off-by: John Hubbard <jhubbard at nvidia.com>
I'm okay with the entire patch set, but I do have a few questions.
> +impl fmt::Display for Spec {
> +??? fn fmt(&self, f: &mut fmt::Formatter<'_>) ->
fmt::Result {
> +??????? write!(
> +??????????? f,
> +??????????? "Chipset: {}, Architecture: {:?}, Revision: {}",
> +??????????? self.chipset,
> +??????????? self.chipset.arch(),
> +??????????? self.revision
> +??????? )
> +??? }
> +}
> +
> ?/// Structure holding the resources required to operate the GPU.
> ?#[pin_data]
> ?pub(crate) struct Gpu {
> @@ -206,13 +218,7 @@ pub(crate) fn new<'a>(
> ???? ) -> impl PinInit<Self, Error> + 'a {
> ???????? try_pin_init!(Self {
> ???????????? spec: Spec::new(bar).inspect(|spec| {
> -??????????????? dev_info!(
> -??????????????????? pdev.as_ref(),
> -??????????????????? "NVIDIA (Chipset: {}, Architecture: {:?},
Revision: {})\n",
> -??????????????????? spec.chipset,
> -??????????????????? spec.chipset.arch(),
> -??????????????????? spec.revision
> -??????????????? );
> +??????????????? dev_info!(pdev.as_ref(),"NVIDIA ({})\n", spec);
I believe that this is the only place where a `Spec` is actually printed.  Does
it really make
sense to implement Display for a single usage?  Do we generally want to
implement Display for
new types?