From a18bc90164e4ce75f2b9f9cb05a6dadaf6953a4f Mon Sep 17 00:00:00 2001
From: Matthew Jackson <1085847+MattJackson@users.noreply.github.com>
Date: Fri, 18 Sep 2026 09:52:27 -0700
Subject: [PATCH] freemkv: source the SET data-in buffer from MIN_ALLOC_LEN
 (single source for the transfer length)

---
 src/freemkv/mod.rs | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/freemkv/mod.rs b/src/freemkv/mod.rs
index 60a08c5..a72aa71 100644
--- a/src/freemkv/mod.rs
+++ b/src/freemkv/mod.rs
@@ -18,8 +18,8 @@
 //! the migrated spec the HRL/AKE/BUS unlock direction is `STATE_OFF`, not `0x01`.
 
 use crate::firmware::{
-    Feature, MEMREAD_LEN, REGION_FREE, RESP_MAGIC, SPEED_MAX, STATE_OFF, build_identity_cdb,
-    build_memread_cdb, build_set_cdb,
+    Feature, MEMREAD_LEN, MIN_ALLOC_LEN, REGION_FREE, RESP_MAGIC, SPEED_MAX, STATE_OFF,
+    build_identity_cdb, build_memread_cdb, build_set_cdb,
 };
 use crate::scsi::{DataDirection, ScsiTransport};
 use crate::{UnlockCtx, UnlockError, Unlocked, Unlocker};
@@ -99,10 +99,10 @@ impl FreemkvUnlocker {
         state: u8,
     ) -> std::result::Result<(), UnlockError> {
         let cdb = build_set_cdb(feature, state);
-        // SET needs the 64-byte data-in phase its CDB advertises — the drive aborts
-        // a no-data SET (CHECK CONDITION / Aborted Command, HW-confirmed on BU40N fw
-        // 0.8.1). Mirror FirmwareControl::set (exec_in): read the table back, ignore it.
-        let mut buf = [0u8; RESP_LEN];
+        // SET needs the data-in phase its CDB advertises — a no-data SET is aborted
+        // (CHECK CONDITION, HW-confirmed on BU40N fw 0.8.1). Buffer sized from the SAME
+        // const the CDB advertises (MIN_ALLOC_LEN) so the transfer length has one source.
+        let mut buf = [0u8; MIN_ALLOC_LEN as usize];
         match scsi.execute(&cdb, DataDirection::FromDevice, &mut buf, 5_000) {
             Ok(r) if r.status == 0 => Ok(()),
             Ok(r) => {