--version: Add better debug messages for parade_retimer

-v or -vv includes the necessary debug info.

Signed-off-by: Daniel Schaefer <dhs@frame.work>

Author: JohnAZoidberg

framework_lib/src/parade_retimer.rs

@@ -10,10 +10,12 @@ use crate::os_specific;
 pub fn get_version(ec: &CrosEc) -> EcResult<Option<Vec<u8>>> {
     let res = EcRequestGetGpuPcie {}.send_command(ec)?;
     let vendor: Option<GpuVendor> = FromPrimitive::from_u8(res.gpu_vendor);
+    info!("GPU vendor: {:?}", vendor);
     if vendor != Some(GpuVendor::NvidiaGn22) {
-        debug!("No compatible retimer present");
+        info!("No compatible retimer present (vendor mismatch)");
         return Ok(None);
     };
+    info!("NVIDIA GPU detected, checking retimer...");
 
     // I2C Port on the EC
     let i2c_port = 5;
@@ -22,19 +24,39 @@ pub fn get_version(ec: &CrosEc) -> EcResult<Option<Vec<u8>>> {
     let i2c_addr = 0x10;
 
     // Check safe mode
+    info!(
+        "Reading retimer at I2C port {} addr 0x{:02X}",
+        i2c_port,
+        i2c_addr >> 1
+    );
     let i2c_response = i2c_read(ec, i2c_port, i2c_addr >> 1, 0x00, 0x01)?;
-    if i2c_response.data[0] == 0 {
+    info!(
+        "I2C response: status=0x{:02X}, data_len={}",
+        i2c_response.i2c_status,
+        i2c_response.data.len()
+    );
+    if i2c_response.i2c_status == 0x01 {
+        // NAK
+        warn!("Unable to communicate with dGPU Retimer. Try to force it on by plugging a cable into the dGPU");
+    }
+    let Some(&safe_mode) = i2c_response.data.first() else {
+        info!("Failed to read retimer safe mode status (empty response)");
+        return Ok(None);
+    };
+    info!("Retimer safe mode status: {}", safe_mode);
+    if safe_mode == 0 {
         // Safe mode not enabled, enable it
         i2c_write(ec, i2c_port, i2c_addr >> 1, 0x00, &[0x01])?;
     }
 
     // Wake up from low power mode
     for _ in 0..3 {
         let i2c_response = i2c_read(ec, i2c_port, (i2c_addr + 2) >> 1, 0x70, 0x01)?;
-        if i2c_response.data[0] != 0 {
-            i2c_write(ec, i2c_port, (i2c_addr + 2) >> 1, 0x70, &[0x00])?;
-            os_specific::sleep(50_000);
+        if i2c_response.data.first() == Some(&0) {
+            continue;
         }
+        i2c_write(ec, i2c_port, (i2c_addr + 2) >> 1, 0x70, &[0x00])?;
+        os_specific::sleep(50_000);
     }
 
     // Read version