satchlj · Oct 31, 2026
@@ -0,0 +1,20 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Apple ISP sensor tuning
+=======================
+
+Stream setup loads model-wide sensor tuning using ``CH_SET_FILE_LOAD``
+(0x0111). A missing file allows streaming with a warning. An invalid file,
+interrupted read or failed firmware upload fails stream setup instead of
+silently continuing. A debug message identifies a successful upload without
+dumping its contents.
+
+Sensor setfiles are distinct from individual camera-module factory
+calibration (iCCl). The driver has no iCCl parser, serial binding or upload
+command. No factory record or vendor payload belongs in the kernel source
+or a distributed firmware package. The separate ANE video denoiser is not
+implemented by this driver.
+
+Command submission alone does not establish the resulting noise reduction
+or qualify a firmware metadata layout. In particular, these error-handling
+changes do not qualify J613 firmware 26.6.2 preview or its image quality.
@@ -12,6 +12,7 @@ Video4Linux (V4L) drivers
 .. toctree::
 	:maxdepth: 5
 
+	apple-isp
 	bttv-devel
 	cx2341x-devel
 	cx88-devel

@@ -14,18 +14,20 @@ config VIDEO_APPLE_ISP
 	  Driver for the image signal processor that runs the built-in
 	  camera of Apple silicon machines. The ISP firmware is loaded by
 	  the bootloader. When a stream starts, the driver loads the
-	  calibration file for the detected camera module,
+	  sensor tuning file for the detected camera model,
 	  apple/isp_<module>_<revision>XX.dat, from the firmware search
-	  path; if it is missing, the stream runs without calibration.
+	  path; if it is missing, the stream runs without sensor tuning.
+	  Invalid files and firmware upload errors fail the stream setup.
+	  These setfiles do not contain per-module factory calibration.
 
 config VIDEO_APPLE_ISP_KUNIT_TEST
 	bool "KUnit tests for the Apple ISP driver" if !KUNIT_ALL_TESTS
 	depends on VIDEO_APPLE_ISP && KUNIT
 	depends on KUNIT=y || VIDEO_APPLE_ISP=m
 	default KUNIT_ALL_TESTS
 	help
-	  Builds unit tests for the videobuf2 queue set-up and for the
-	  shared memory the firmware frees into the Apple ISP driver. They
+	  Builds unit tests for sensor tuning setup, the videobuf2 queue
+	  and shared memory the firmware frees into the Apple ISP driver. They
 	  need no hardware. Only useful for kernel developers running KUnit.
 
 	  If unsure, say N.

@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Setfile setup boundary tests; no firmware data or hardware access. */
+#include <kunit/test.h>
+#include <kunit/static_stub.h>
+#include <kunit/device.h>
+#include "isp-ipc.h"
+
+struct isp_test_command_trace {
+	unsigned int count;
+	unsigned int fail_at;
+	int setfile_error;
+	unsigned int setfile_calls;
+};
+
+static int isp_test_send(struct apple_isp *isp, struct isp_channel *chan,
+			 unsigned long timeout)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct isp_test_command_trace *trace = test->priv;
+	u32 *words = isp->cmd_virt;
+
+	trace->count++;
+	KUNIT_EXPECT_EQ(test, words[1], trace->count == 1 ?
+			 CISP_CMD_FLICKER_SENSOR_SET : CISP_CMD_CH_SBS_ENABLE);
+	return trace->count == trace->fail_at ? -ETIME : 0;
+}
+
+static struct apple_isp *isp_test_capture_alloc(struct kunit *test)
+{
+	static const struct apple_isp_hw hw = { };
+	struct apple_isp *isp = kunit_kzalloc(test, sizeof(*isp), GFP_KERNEL);
+
+	KUNIT_ASSERT_NOT_NULL(test, isp);
+	isp->dev = kunit_device_register(test, "apple-isp-setfile-test");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, isp->dev);
+	isp->hw = &hw;
+	isp->chan_io = kunit_kzalloc(test, sizeof(*isp->chan_io), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, isp->chan_io);
+	isp->chan_io->name = "test";
+	isp->cmd_virt = kunit_kzalloc(test, 256, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, isp->cmd_virt);
+	kunit_activate_static_stub(test, ipc_chan_send, isp_test_send);
+	return isp;
+}
+
+static int isp_test_load_setfile(struct apple_isp *isp, u32 ch)
+{
+	struct kunit *test = kunit_get_current_test();
+	struct isp_test_command_trace *trace = test->priv;
+
+	trace->setfile_calls++;
+	return trace->setfile_error;
+}
+
+static void isp_test_setfile_failure_stops_setup(struct kunit *test)
+{
+	static const int errors[] = { -EINVAL, -EIO, -ETIME, -EINTR, -ENOMEM };
+	struct apple_isp *isp = isp_test_capture_alloc(test);
+	struct isp_test_command_trace trace;
+
+	kunit_activate_static_stub(test, isp_ch_load_setfile, isp_test_load_setfile);
+	test->priv = &trace;
+	for (unsigned int i = 0; i < ARRAY_SIZE(errors); i++) {
+		trace = (struct isp_test_command_trace){ .setfile_error = errors[i] };
+		KUNIT_EXPECT_EQ(test, isp_ch_configure_capture(isp, 0), errors[i]);
+		/* Only the flicker command preceded the rejected tuning. */
+		KUNIT_EXPECT_EQ(test, trace.count, 1);
+		KUNIT_EXPECT_EQ(test, trace.setfile_calls, 1);
+	}
+}
+
+static void isp_test_optional_setfile_continues_setup(struct kunit *test)
+{
+	static const int results[] = { 0, -ENOENT };
+	struct apple_isp *isp = isp_test_capture_alloc(test);
+	struct isp_test_command_trace trace;
+
+	kunit_activate_static_stub(test, isp_ch_load_setfile, isp_test_load_setfile);
+	test->priv = &trace;
+	for (unsigned int i = 0; i < ARRAY_SIZE(results); i++) {
+		trace = (struct isp_test_command_trace){
+			.setfile_error = results[i], .fail_at = 2,
+		};
+		/* The SBS command after tuning, rather than tuning, fails. */
+		KUNIT_EXPECT_EQ(test, isp_ch_configure_capture(isp, 0), -ETIME);
+		KUNIT_EXPECT_EQ(test, trace.count, 2);
+		KUNIT_EXPECT_EQ(test, trace.setfile_calls, 1);
+	}
+}
+
+static struct kunit_case isp_cam_test_cases[] = {
+	KUNIT_CASE(isp_test_setfile_failure_stops_setup),
+	KUNIT_CASE(isp_test_optional_setfile_continues_setup),
+	{}
+};
+
+static struct kunit_suite isp_cam_test_suite = {
+	.name = "apple-isp-cam",
+	.test_cases = isp_cam_test_cases,
+};
+
+kunit_test_suite(isp_cam_test_suite);
@@ -3,6 +3,7 @@
 
 #include <linux/firmware.h>
 #include <linux/unaligned.h>
+#include <kunit/static_stub.h>
 
 #include "isp-cam.h"
 #include "isp-cmd.h"
@@ -343,14 +344,20 @@ static int isp_ch_load_setfile(struct apple_isp *isp, u32 ch)
 	u32 magic;
 	int err;
 
+	KUNIT_STATIC_STUB_REDIRECT(isp_ch_load_setfile, isp, ch);
+
 	if (WARN_ON_ONCE(setfile->size > isp->data_surf->size))
 		return -ENOSPC;
 
 	err = firmware_request_nowarn(&fw, setfile->path, isp->dev);
 	if (err) {
-		dev_warn_once(isp->dev,
-			      "setfile '%s' not loaded (%d), streaming without calibration\n",
-			      setfile->path, err);
+		if (err == -ENOENT)
+			dev_warn_once(isp->dev,
+				      "setfile '%s' missing, streaming without sensor tuning\n",
+				      setfile->path);
+		else
+			dev_err(isp->dev, "failed to read setfile '%s': %d\n",
+				setfile->path, err);
 		return err;
 	}
 
@@ -373,8 +380,16 @@ static int isp_ch_load_setfile(struct apple_isp *isp, u32 ch)
 	memset(isp->data_surf->virt + len, 0, setfile->size - len);
 	release_firmware(fw);
 
-	return isp_cmd_ch_set_file_load(isp, ch, isp->data_surf->iova,
-					setfile->size);
+	err = isp_cmd_ch_set_file_load(isp, ch, isp->data_surf->iova,
+				       setfile->size);
+	if (err)
+		dev_err(isp->dev, "ch %u: setfile '%s' load failed: %d\n",
+			ch, setfile->path, err);
+	else
+		dev_dbg(isp->dev, "ch %u: loaded sensor tuning '%s' (0x%zx bytes)\n",
+			ch, setfile->path, setfile->size);
+
+	return err;
 }
 
 static int isp_ch_configure_frame_rate(struct apple_isp *isp, u32 ch)
@@ -432,11 +447,12 @@ static int isp_ch_configure_capture(struct apple_isp *isp, u32 ch)
 	isp_cmd_flicker_sensor_set(isp, 0);
 
 	/*
-	 * The setfile isn't requisite but then we don't get calibration. If
-	 * loading it was interrupted by a signal, give up on the stream.
+	 * Missing sensor tuning is optional. A present but invalid setfile or
+	 * a failed firmware upload must not silently select firmware defaults.
+	 * This model-wide tuning is separate from per-module factory data.
 	 */
 	err = isp_ch_load_setfile(isp, ch);
-	if (err == -EINTR)
+	if (err && err != -ENOENT)
 		return err;
 
 	if (isp->hw->lpdp) {
@@ -661,3 +677,7 @@ void apple_isp_stop_capture(struct apple_isp *isp)
 	/* ... until its buffers are back. */
 	apple_isp_wdt_stop(isp);
 }
+
+#if IS_ENABLED(CONFIG_VIDEO_APPLE_ISP_KUNIT_TEST)
+#include "isp-cam-test.c"
+#endif
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /* Copyright 2023 Eileen Yoon <eyn@gmx.com> */
 
+#include <kunit/static_stub.h>
+
 #include "isp-iommu.h"
 #include "isp-ipc.h"
 #include "isp-regs.h"
@@ -176,6 +178,8 @@ int ipc_chan_send(struct apple_isp *isp, struct isp_channel *chan,
 {
 	long t;
 
+	KUNIT_STATIC_STUB_REDIRECT(ipc_chan_send, isp, chan, timeout);
+
 	chan_write_msg(isp, chan, &chan->req);
 	dma_wmb();