Reset the pci-testdev when the driver is unbound from its device.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 samples/rust/rust_driver_pci.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs
index 15147e4401b2..062a242f8874 100644
--- a/samples/rust/rust_driver_pci.rs
+++ b/samples/rust/rust_driver_pci.rs
@@ -18,7 +18,7 @@ impl Regs {
 
 type Bar0 = pci::Bar<{ Regs::END }>;
 
-#[derive(Debug)]
+#[derive(Copy, Clone, Debug)]
 struct TestIndex(u8);
 
 impl TestIndex {
@@ -28,6 +28,7 @@ impl TestIndex {
 struct SampleDriver {
     pdev: ARef<pci::Device>,
     bar: Devres<Bar0>,
+    index: TestIndex,
 }
 
 kernel::pci_device_table!(
@@ -79,6 +80,7 @@ fn probe(pdev: &pci::Device<Core>, info: &Self::IdInfo) -> Result<Pin<KBox<Self>
             Self {
                 pdev: pdev.into(),
                 bar,
+                index: *info,
             },
             GFP_KERNEL,
         )?;
@@ -92,6 +94,13 @@ fn probe(pdev: &pci::Device<Core>, info: &Self::IdInfo) -> Result<Pin<KBox<Self>
 
         Ok(drvdata.into())
     }
+
+    fn unbind(pdev: &pci::Device<Core>, this: Pin<&Self>) {
+        if let Ok(bar) = this.bar.access(pdev.as_ref()) {
+            // Reset pci-testdev by writing a new test index.
+            bar.write8(this.index.0, Regs::TEST);
+        }
+    }
 }
 
 impl Drop for SampleDriver {
-- 
2.49.0