Claude review: drm/i915/dp: Fix readback for target_rr in Adaptive Sync SDP

Claude Code Review Bot
2026-04-12T02:51:26Z

Patch Review

**R-b: Ville Syrjala, Fixes tag present**

This is a real bug fix. The old code:
```c
as_sdp->target_rr = (u64)sdp->db[3] | ((u64)sdp->db[4] & 0x3);
```
is wrong -- it ORs db[4] bits[1:0] into bits[1:0] of db[3] instead of shifting them to bits[9:8]. The fix:
```c
as_sdp->target_rr = ((sdp->db[4] & 0x3) << 8) | sdp->db[3];
```

This matches the pack function which does `(as_sdp->target_rr >> 8) & 0x3` into db[4] and `target_rr & 0xFF` into db[3].

Good fix. Should be backported to stable.