Remove SpeedTable, add probe_disc(), named constants, clean architecture

- Removed SpeedTable entirely — drive manages speeds after probe
- Renamed read_speed_table() → probe_disc()
- Named all SCSI constants: SUB_CMD_UNLOCK, SUB_CMD_INIT, SUB_CMD_PROBE,
  INIT_ADDR_BD, INIT_ADDR_UHD, PROBE_COARSE_END, PROBE_FINE_END, etc.
- Auto-detect BD vs UHD from disc capacity for correct probe init address
- Fixed NOMINAL_SPEED_B (was invalid CDB, removed — single max instead)
- Added session.set_speed() for simple speed control
- Error recovery: re-init on first error, BD2x on repeated errors
- Batch size uses full kernel limit (was 80%, now 100%)
- Clean variant_a/variant_b with named constants

API: open() → wait_ready() → init() → probe_disc() → scan() → read

src/speed.rs

@@ -1,133 +1,6 @@
-//! Drive speed management — zone-based speed table.
-//!
-//! Every DriveSession has a SpeedTable. Default: max speed everywhere.
-//! After init(): calibrated per-zone speeds from disc surface probes.
-//! One u32 comparison per read on the hot path.
+//! Drive speed constants.
 
-/// Speed table — maps disc positions to optimal read speeds.
-#[derive(Debug, Clone)]
-pub struct SpeedTable {
-    zones: Vec<(u32, u16)>,  // (start_lba, speed_kbs), sorted by lba
-    current_speed: u16,
-    next_boundary: u32,
-}
-
-impl SpeedTable {
-    /// Default: max speed, whole disc. Drive manages itself.
-    pub fn new() -> Self {
-        SpeedTable {
-            zones: vec![(0, 0xFFFF)],
-            current_speed: 0,       // force first SET_CD_SPEED
-            next_boundary: 0,       // force first lookup
-        }
-    }
-
-    /// Hot path: has the speed zone changed for this LBA?
-    /// Returns Some(speed_kbs) only when a SET_CD_SPEED is needed.
-    #[inline]
-    pub fn speed_for(&mut self, lba: u32) -> Option<u16> {
-        if lba < self.next_boundary {
-            return None;
-        }
-        self.transition(lba)
-    }
-
-    /// Zone transition — lookup + precompute next boundary.
-    fn transition(&mut self, lba: u32) -> Option<u16> {
-        let mut zone_idx = 0;
-        for (i, &(start, _)) in self.zones.iter().enumerate() {
-            if start <= lba {
-                zone_idx = i;
-            } else {
-                break;
-            }
-        }
-
-        let speed = self.zones[zone_idx].1;
-
-        self.next_boundary = if zone_idx + 1 < self.zones.len() {
-            self.zones[zone_idx + 1].0
-        } else {
-            u32::MAX
-        };
-
-        if speed == self.current_speed {
-            return None;
-        }
-
-        self.current_speed = speed;
-        Some(speed)
-    }
-
-    /// Load calibrated zones. Converts from platform probe data to generic (lba, kbs).
-    /// `disc_sectors`: total disc capacity from READ CAPACITY.
-    /// `probes`: (probe_address, speed_index) pairs from calibration scan.
-    /// `probe_range`: max probe address space (0x10000 for MT1959).
-    /// `speed_multiplier`: KB/s per speed unit (4500 for BD 1x).
-    pub fn load_calibration(
-        &mut self,
-        disc_sectors: u32,
-        probes: &[(u16, u8)],
-        probe_range: u32,
-        speed_multiplier: u16,
-    ) {
-        if probes.is_empty() || disc_sectors == 0 {
-            return;
-        }
-
-        let mut zones: Vec<(u32, u16)> = Vec::new();
-
-        for &(probe_addr, speed_idx) in probes {
-            let lba = (probe_addr as u64 * disc_sectors as u64 / probe_range as u64) as u32;
-            let kbs = speed_idx as u16 * speed_multiplier;
-            zones.push((lba, kbs));
-        }
-
-        zones.sort_by_key(|&(lba, _)| lba);
-
-        // Deduplicate: keep only zone boundaries where speed changes
-        let mut deduped: Vec<(u32, u16)> = Vec::new();
-        for &(lba, kbs) in &zones {
-            if deduped.last().map_or(true, |&(_, prev_kbs)| prev_kbs != kbs) {
-                deduped.push((lba, kbs));
-            }
-        }
-
-        if deduped.is_empty() {
-            return;
-        }
-
-        self.zones = deduped;
-        self.current_speed = 0;
-        self.next_boundary = 0;
-    }
-
-    /// Temporarily reduce speed for error recovery.
-    pub fn reduce(&mut self) -> u16 {
-        let speed = (self.current_speed / 2).max(4500);
-        self.current_speed = speed;
-        speed
-    }
-
-    /// Resume table-driven speed at this LBA.
-    pub fn resume(&mut self, lba: u32) {
-        self.current_speed = 0;
-        self.next_boundary = 0;
-        self.transition(lba);
-    }
-
-    /// Current speed in KB/s.
-    pub fn current(&self) -> u16 {
-        self.current_speed
-    }
-
-    /// Number of zones.
-    pub fn zone_count(&self) -> usize {
-        self.zones.len()
-    }
-}
-
-// Keep DriveSpeed enum for CLI display
+/// Common optical drive speeds with KB/s values for SET_CD_SPEED.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum DriveSpeed {
     BD1x, BD2x, BD4x, BD6x, BD8x, BD10x, BD12x,