docs: correct i2cdetect usage and ignore archived notes

The engine exposes only SMBus BYTE_DATA/WORD_DATA, so i2cdetect (which
needs SMBus QUICK or READ_BYTE) cannot scan the bus. Replace the
misleading "i2cdetect -r/-y" scan instructions with a direct i2cget
byte-data read in the README, the cover letter and the smoke test.

Also gitignore the archived internal working documents
(docs/archive-*.md).

Signed-off-by: Simone Chifari <simone.chifari@gmail.com>

.gitignore

@@ -43,11 +43,12 @@ patches/
 
 # Internal working documents (not for public repo)
 TODO.md
-submission-analysis.md
+docs/archive-submission-analysis.md
 README.local.md
 AGENTS.md
 docs/mainline-plan.md
 docs/archive-i2c-imc-driver-plan.md
+docs/archive-v3-review-fixes.md
 docs/submission/submission-instructions.md
 
 # Private Gitea CI (replaced by .github/workflows/ for public repo)

README.md

@@ -111,9 +111,9 @@ i2c-6   smbus           iMC SMBus Skylake-X channel 0                SMBus adapt
 i2c-7   smbus           iMC SMBus Skylake-X channel 1                SMBus adapter
 ```
 
-You can scan for SPD EEPROMs (usually located at addresses `0x50-0x57`) on channel 0:
+The engine has no SMBus QUICK/BYTE primitive, so `i2cdetect` cannot scan the bus. Read a device directly with a byte-data access (a register offset is always required), e.g. SPD byte 2 (DDR4 type code `0x0c`) from the EEPROM at `0x50` on channel 0:
 ```bash
-sudo i2cdetect -y 6
+sudo i2cget -y 6 0x50 0x02
 ```
 
 ---

docs/submission/cover-letter.txt

@@ -89,8 +89,9 @@ on both read and write paths.
 
 Since the hardware requires a register offset for every transaction,
 I2C_SMBUS_QUICK and I2C_SMBUS_BYTE (which have no offset) are not supported
-(returning -EOPNOTSUPP).  Use `i2cdetect -r` (read byte data probe) to scan
-for devices.  Standard kernel drivers such as ee1004 (for DDR4 SPD) load
+(returning -EOPNOTSUPP).  For the same reason i2cdetect cannot scan the bus;
+access a device directly with a byte-data read, e.g. `i2cget -y <bus> 0x50 0x02`
+reads SPD byte 2.  Standard kernel drivers such as ee1004 (for DDR4 SPD) load
 and bind successfully via BYTE_DATA reads.
 
 udev autoloads the module on PCI add event (MODULE_DEVICE_TABLE present).

test-smoke.sh

@@ -32,13 +32,25 @@ else
 	_fail "ch1 adapter not found"
 fi
 
+# The engine has no QUICK/BYTE primitive, so `i2cdetect` cannot scan the bus
+# ("Bus doesn't support detection commands"). Probe SPD addresses directly with
+# a byte-data read of register 0x00 instead.
+_scan_spd() {
+	local bus=$1 found=""
+	echo "--- SPD scan bus $bus (byte-data read of reg 0x00) ---"
+	for a in 0x50 0x51 0x52 0x53 0x54 0x55 0x56 0x57; do
+		if v=$(i2cget -y "$bus" "$a" 0x00 2>/dev/null); then
+			echo "  $a present (reg0=$v)"
+			found="$a"
+		fi
+	done
+	[ -n "$found" ]
+}
+
 if [ -n "$CH0" ]; then
 	echo ""
-	echo "=== SPD scan ch0 (expect 0x50-0x57) ==="
-	i2cdetect -r -y "$CH0" 2>/dev/null
-	# at least one SPD slot must respond
-	if i2cdetect -r -y "$CH0" 2>/dev/null | grep '50' >/dev/null; then
-		_ok "SPD device at 0x50 on ch0"
+	if _scan_spd "$CH0"; then
+		_ok "SPD device present on ch0"
 	else
 		_fail "no SPD device on ch0"
 	fi
@@ -46,8 +58,7 @@ fi
 
 if [ -n "$CH1" ]; then
 	echo ""
-	echo "=== SPD scan ch1 ==="
-	i2cdetect -r -y "$CH1" 2>/dev/null
+	_scan_spd "$CH1" && _ok "SPD device present on ch1" || true
 fi
 
 echo ""