[PATCH 0/5] Improve ACPI detection code for atomisp

[PATCH 0/5] Improve ACPI detection code for atomisp

[Mauro Carvalho Chehab]

Add support to read the sensor configuration directly from the BIOS,
instead of relying on DMI match tables.

As we don't have the legacy models there which has their own
DMI match tables, we can't remove them, but this change should
make this driver to better detect unlisted devices.

Mauro Carvalho Chehab (5):
  media: atomisp: improve sensor detection code to use _DSM table
  Revert "media: atomisp: Add some ACPI detection info"
  Revert "media: atomisp: add Asus Transform T101HA ACPI vars"
  media: atomisp: change clock source default for ISP2401
  media: atomisp: improve ACPI/DMI detection logs

 drivers/staging/media/atomisp/TODO            |  43 +----
 .../media/atomisp/i2c/atomisp-gc0310.c        |  11 --
 .../media/atomisp/i2c/atomisp-gc2235.c        |  11 --
 .../media/atomisp/i2c/atomisp-lm3554.c        |  11 --
 .../media/atomisp/i2c/atomisp-mt9m114.c       |  11 --
 .../media/atomisp/i2c/atomisp-ov2680.c        |  11 --
 .../media/atomisp/i2c/atomisp-ov2722.c        |  11 --
 .../media/atomisp/i2c/ov5693/atomisp-ov5693.c |  11 --
 .../media/atomisp/pci/atomisp_gmin_platform.c | 157 ++++++++++++++----
 9 files changed, 129 insertions(+), 148 deletions(-)

-- 
2.26.2

[PATCH 1/5] media: atomisp: improve sensor detection code to use _DSM table

[Mauro Carvalho Chehab]

Instead of keep hardcoding device-specific tables, read them
directly from the ACPI BIOS, if available.

This method is know to work with Asus T101HA device. the
same table is also visible on EzPad devices. So, it seems
that at least some BIOSes use this method to pass data about
ISP2401-connected sensors.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/atomisp/TODO            |  43 +------
 .../media/atomisp/pci/atomisp_gmin_platform.c | 105 +++++++++++++++++-
 2 files changed, 101 insertions(+), 47 deletions(-)

diff --git a/drivers/staging/media/atomisp/TODO b/drivers/staging/media/atomisp/TODO
index 9e46015ebcd5..6cf90ccf3cf8 100644
--- a/drivers/staging/media/atomisp/TODO
+++ b/drivers/staging/media/atomisp/TODO
@@ -18,48 +18,7 @@ TODO
    This should be converted to the usual way, using V4L2 async subdev
    framework to wait for cameras to be probed;
 
-2. Support for newer board-specific data (like Asus T101HA support) uses a
-   DMI match table to retrieve sensor's data, using hard-coded values.
-   It sounds feasible to retrieve those data directly from ACPI via _DSM
-   tables (like this one, associated with CAM1 at the above mentioned
-   hardware):
-
-            Name (C1CD, Buffer (0x0220){})
-            Method (_DSM, 4, NotSerialized)  // _DSM: Device-Specific Method
-            {
-                If ((Arg0 == ToUUID ("dc2f6c4f-045b-4f1d-97b9-882a6860a4be")))
-                {
-                    Local0 = Package (0x12)
-                        {
-                            "CamId",
-                            "ov2680",
-                            "CamType",
-                            "1",
-                            "CsiPort",
-                            "0",
-                            "CsiLanes",
-                            "1",
-                            "CsiFmt",
-                            "15",
-                            "CsiBayer",
-                            "0",
-                            "CamClk",
-                            "1",
-                            "Regulator1p8v",
-                            "0",
-                            "Regulator2p8v",
-                            "0"
-                        }
-                    Return (Local0)
-                }
-
-   The code there at atomisp_gmin_platform has an EFI parser, but it
-   assumes that the information would be stored on a different way.
-
-   As the Kernel has support for reading data from _DSM, via
-   acpi_evaluate_dsm(), it sounds doable to use such infra and remove the
-   DMI match, at least for some devices. This will likely allow covering
-   more devices that could also be using the same EFI UUID.
+2. Use ACPI _DSM table - DONE!
 
 3. Switch the driver to use pm_runtime stuff. Right now, it probes the
    existing PMIC code and sensors call it directly.
diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index 5d2bfe2ea971..5f34b2be5153 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -388,6 +388,10 @@ static const struct dmi_system_id gmin_vars[] = {
 				       0xa9, 0x71, 0xe8, 0x77,	   \
 				       0x75, 0x60, 0x68, 0xf7)
 
+static const guid_t atomisp_dsm_guid = GUID_INIT(0xdc2f6c4f, 0x045b, 0x4f1d,
+						 0x97, 0xb9, 0x88, 0x2a,
+						 0x68, 0x60, 0xa4, 0xbe);
+
 #define CFG_VAR_NAME_MAX 64
 
 #define GMIN_PMC_CLK_NAME 14 /* "pmc_plt_clk_[0..5]" */
@@ -455,15 +459,28 @@ static int gmin_i2c_write(struct device *dev, u16 i2c_addr, u8 reg,
 
 static struct gmin_subdev *gmin_subdev_add(struct v4l2_subdev *subdev)
 {
-	int i, ret;
-	struct device *dev;
 	struct i2c_client *power = NULL, *client = v4l2_get_subdevdata(subdev);
+	struct acpi_device *adev;
+	acpi_handle handle;
+	struct device *dev;
+	int i, ret;
 
 	if (!client)
 		return NULL;
 
 	dev = &client->dev;
 
+	handle = ACPI_HANDLE(dev);
+
+	// FIXME: may need to release resources allocated by acpi_bus_get_device()
+	if (!handle || acpi_bus_get_device(handle, &adev)) {
+		dev_err(dev, "Error could not get ACPI device\n");
+		return NULL;
+	}
+
+	dev_info(&client->dev, "%s: ACPI detected it on bus ID=%s, HID=%s\n",
+		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
+
 	if (!pmic_id) {
 		if (gmin_i2c_dev_exists(dev, PMIC_ACPI_TI, &power))
 			pmic_id = PMIC_TI;
@@ -944,6 +961,75 @@ static int gmin_get_hardcoded_var(struct gmin_cfg_var *varlist,
 	return -EINVAL;
 }
 
+
+static int gmin_get_config_dsm_var(struct device *dev,
+				   const char *var,
+				   char *out, size_t *out_len)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object *obj, *cur = NULL;
+	int i;
+
+	obj = acpi_evaluate_dsm(handle, &atomisp_dsm_guid, 0, 0, NULL);
+	if (!obj) {
+		dev_info_once(dev, "Didn't find ACPI _DSM table.\n");
+		return -EINVAL;
+	}
+
+#if 0 /* Just for debugging purposes */
+	for (i = 0; i < obj->package.count; i++) {
+		union acpi_object *cur = &obj->package.elements[i];
+
+		if (cur->type == ACPI_TYPE_INTEGER)
+			dev_info(dev, "object #%d, type %d, value: %lld\n",
+				 i, cur->type, cur->integer.value);
+		else if (cur->type == ACPI_TYPE_STRING)
+			dev_info(dev, "object #%d, type %d, string: %s\n",
+				 i, cur->type, cur->string.pointer);
+		else
+			dev_info(dev, "object #%d, type %d\n",
+				 i, cur->type);
+	}
+#endif
+
+	/* Seek for the desired var */
+	for (i = 0; i < obj->package.count - 1; i += 2) {
+		if (obj->package.elements[i].type == ACPI_TYPE_STRING &&
+		    !strcmp(obj->package.elements[i].string.pointer, var)) {
+			/* Next element should be the required value */
+			cur = &obj->package.elements[i + 1];
+			break;
+		}
+	}
+
+	if (!cur) {
+		dev_info(dev, "didn't found _DSM entry for '%s'\n", var);
+		ACPI_FREE(obj);
+		return -EINVAL;
+	}
+
+	/*
+	 * While it could be possible to have an ACPI_TYPE_INTEGER,
+	 * and read the value from cur->integer.value, the table
+	 * seen so far uses the string type. So, produce a warning
+	 * if it founds something different than string, letting it
+	 * to fall back to the old code.
+	 */
+	if (cur && cur->type != ACPI_TYPE_STRING) {
+		dev_info(dev, "found non-string _DSM entry for '%s'\n", var);
+		ACPI_FREE(obj);
+		return -EINVAL;
+	}
+
+	dev_info(dev, "found _DSM entry for '%s': %s\n", var,
+		 cur->string.pointer);
+	strscpy(out, cur->string.pointer, *out_len);
+	*out_len = strlen(cur->string.pointer);
+
+	ACPI_FREE(obj);
+	return 0;
+}
+
 /* Retrieves a device-specific configuration variable.  The dev
  * argument should be a device with an ACPI companion, as all
  * configuration is based on firmware ID.
@@ -953,12 +1039,21 @@ static int gmin_get_config_var(struct device *maindev,
 			       const char *var,
 			       char *out, size_t *out_len)
 {
-	char var8[CFG_VAR_NAME_MAX];
 	efi_char16_t var16[CFG_VAR_NAME_MAX];
-	struct efivar_entry *ev;
 	const struct dmi_system_id *id;
-	int i, ret;
 	struct device *dev = maindev;
+	char var8[CFG_VAR_NAME_MAX];
+	struct efivar_entry *ev;
+	int i, ret;
+
+	/* For sensors, try first to use the _DSM table */
+	if (!is_gmin) {
+		ret = gmin_get_config_dsm_var(maindev, var, out, out_len);
+		if (!ret)
+			return 0;
+	}
+
+	/* Fall-back to other approaches */
 
 	if (!is_gmin && ACPI_COMPANION(dev))
 		dev = &ACPI_COMPANION(dev)->dev;
-- 
2.26.2

[PATCH 2/5] Revert "media: atomisp: Add some ACPI detection info"

[Mauro Carvalho Chehab]

This reverts commit 0d64e9420583cbc3c4a3f949ebe38fd8f7769281.

As gmin_subdev_add() now takes the ACPI handle directly,
we can deprecate the code that were doing this inside each
I2C driver.

PS.: This also reverts commit c03496b3bd92 ("media: atomisp: add a notice about possible leak resources")

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/staging/media/atomisp/i2c/atomisp-gc0310.c    | 11 -----------
 drivers/staging/media/atomisp/i2c/atomisp-gc2235.c    | 11 -----------
 drivers/staging/media/atomisp/i2c/atomisp-lm3554.c    | 11 -----------
 drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c   | 11 -----------
 drivers/staging/media/atomisp/i2c/atomisp-ov2680.c    | 11 -----------
 drivers/staging/media/atomisp/i2c/atomisp-ov2722.c    | 11 -----------
 .../staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c | 11 -----------
 7 files changed, 77 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
index 3fbd585d45ed..2b71de722ec3 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-gc0310.c
@@ -1310,17 +1310,6 @@ static int gc0310_probe(struct i2c_client *client)
 	int ret;
 	void *pdata;
 	unsigned int i;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
diff --git a/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c b/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
index ae36dd4e9d0f..78147ffb6099 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-gc2235.c
@@ -1052,17 +1052,6 @@ static int gc2235_probe(struct i2c_client *client)
 	void *gcpdev;
 	int ret;
 	unsigned int i;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
index 85c90c663613..809010af7855 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
@@ -851,17 +851,6 @@ static int lm3554_probe(struct i2c_client *client)
 	struct lm3554 *flash;
 	unsigned int i;
 	int ret;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	flash = kzalloc(sizeof(*flash), GFP_KERNEL);
 	if (!flash)
diff --git a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
index a76031f9c799..0d60918a9b19 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-mt9m114.c
@@ -1817,17 +1817,6 @@ static int mt9m114_probe(struct i2c_client *client)
 	int ret = 0;
 	unsigned int i;
 	void *pdata;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	/* Setup sensor configuration structure */
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
diff --git a/drivers/staging/media/atomisp/i2c/atomisp-ov2680.c b/drivers/staging/media/atomisp/i2c/atomisp-ov2680.c
index 8f548351142a..90d125ba080f 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-ov2680.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-ov2680.c
@@ -1244,17 +1244,6 @@ static int ov2680_probe(struct i2c_client *client)
 	int ret;
 	void *pdata;
 	unsigned int i;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	dev_info(&client->dev, "%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
diff --git a/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c b/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
index 9f3e99be810d..eecefcd734d0 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-ov2722.c
@@ -1215,17 +1215,6 @@ static int ov2722_probe(struct i2c_client *client)
 	struct ov2722_device *dev;
 	void *ovpdev;
 	int ret;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
diff --git a/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c b/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
index da5b1a31e82f..97ab10bc45ca 100644
--- a/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
+++ b/drivers/staging/media/atomisp/i2c/ov5693/atomisp-ov5693.c
@@ -1902,17 +1902,6 @@ static int ov5693_probe(struct i2c_client *client)
 	int ret = 0;
 	void *pdata;
 	unsigned int i;
-	acpi_handle handle;
-	struct acpi_device *adev;
-
-	handle = ACPI_HANDLE(&client->dev);
-	if (!handle || acpi_bus_get_device(handle, &adev)) {
-		dev_err(&client->dev, "Error could not get ACPI device\n");
-		return -ENODEV;
-	}
-	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
-		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
-	// FIXME: may need to release resources allocated by acpi_bus_get_device()
 
 	/*
 	 * Firmware workaround: Some modules use a "secondary default"
-- 
2.26.2

[PATCH 3/5] Revert "media: atomisp: add Asus Transform T101HA ACPI vars"

[Mauro Carvalho Chehab]

Now that the EFI _DSM table is parsed by the driver, we don't
need a DMI match anymore for Asus Transform T101HA.

This reverts commit 0a76fd8e8d202dcaabc714850205d5d75c9b8271.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../media/atomisp/pci/atomisp_gmin_platform.c    | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index 5f34b2be5153..cb02806274d1 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -328,15 +328,6 @@ static struct gmin_cfg_var i8880_vars[] = {
 	{},
 };
 
-static struct gmin_cfg_var asus_vars[] = {
-	{"OVTI2680:00_CsiPort", "1"},
-	{"OVTI2680:00_CsiLanes", "1"},
-	{"OVTI2680:00_CsiFmt", "15"},
-	{"OVTI2680:00_CsiBayer", "0"},
-	{"OVTI2680:00_CamClk", "1"},
-	{},
-};
-
 static const struct dmi_system_id gmin_vars[] = {
 	{
 		.ident = "BYT-T FFD8",
@@ -374,13 +365,6 @@ static const struct dmi_system_id gmin_vars[] = {
 		},
 		.driver_data = i8880_vars,
 	},
-	{
-		.ident = "T101HA",
-		.matches = {
-			DMI_MATCH(DMI_BOARD_NAME, "T101HA"),
-		},
-		.driver_data = asus_vars,
-	},
 	{}
 };
 
-- 
2.26.2

[PATCH 4/5] media: atomisp: change clock source default for ISP2401

[Mauro Carvalho Chehab]

There's a notice there stating that the PLL is not reliable
for CHT. Yet, it tries to read it via the BIOS. Well,
this will fail (at least with the devices I checked the
DSDT tables). So, change the logic in a way that it will
change the default, depending on the ISP version.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../media/atomisp/pci/atomisp_gmin_platform.c  | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index cb02806274d1..a14326111b26 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -493,9 +493,23 @@ static struct gmin_subdev *gmin_subdev_add(struct v4l2_subdev *subdev)
 
 	gmin_subdevs[i].subdev = subdev;
 	gmin_subdevs[i].clock_num = gmin_get_var_int(dev, false, "CamClk", 0);
-	/*WA:CHT requires XTAL clock as PLL is not stable.*/
+	/*
+	 * FIXME:
+	 * 	WA:CHT requires XTAL clock as PLL is not stable.
+	 *
+	 * However, such data doesn't seem to be present at the _DSM
+	 * table under the GUID dc2f6c4f-045b-4f1d-97b9-882a6860a4be.
+	 * So, let's change the default according with the ISP version,
+	 * but allowing it to be overridden by BIOS or by DMI match tables.
+	 */
+	if (IS_ISP2401)
+		gmin_subdevs[i].clock_src = VLV2_CLK_XTAL_25_0MHz;
+	else
+		gmin_subdevs[i].clock_src = VLV2_CLK_PLL_19P2MHZ;
+
 	gmin_subdevs[i].clock_src = gmin_get_var_int(dev, false, "ClkSrc",
-				    VLV2_CLK_PLL_19P2MHZ);
+						     gmin_subdevs[i].clock_src);
+
 	gmin_subdevs[i].csi_port = gmin_get_var_int(dev, false, "CsiPort", 0);
 	gmin_subdevs[i].csi_lanes = gmin_get_var_int(dev, false, "CsiLanes", 1);
 
-- 
2.26.2

[PATCH 5/5] media: atomisp: improve ACPI/DMI detection logs

[Mauro Carvalho Chehab]

As there are several ways where the driver could possible
retrieve sensor data, make the prints clearer about what
was detected and from where.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 .../media/atomisp/pci/atomisp_gmin_platform.c  | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index a14326111b26..1ba03448d348 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -936,7 +936,8 @@ int atomisp_gmin_register_vcm_control(struct camera_vcm_control *vcmCtrl)
 }
 EXPORT_SYMBOL_GPL(atomisp_gmin_register_vcm_control);
 
-static int gmin_get_hardcoded_var(struct gmin_cfg_var *varlist,
+static int gmin_get_hardcoded_var(struct device *dev,
+				  struct gmin_cfg_var *varlist,
 				  const char *var8, char *out, size_t *out_len)
 {
 	struct gmin_cfg_var *gv;
@@ -947,6 +948,8 @@ static int gmin_get_hardcoded_var(struct gmin_cfg_var *varlist,
 		if (strcmp(var8, gv->name))
 			continue;
 
+		dev_info(dev, "Found DMI entry for '%s'\n", var8);
+
 		vl = strlen(gv->val);
 		if (vl > *out_len - 1)
 			return -ENOSPC;
@@ -1070,9 +1073,10 @@ static int gmin_get_config_var(struct device *maindev,
 	 */
 	id = dmi_first_match(gmin_vars);
 	if (id) {
-		dev_info(maindev, "Found DMI entry for '%s'\n", var8);
-		return gmin_get_hardcoded_var(id->driver_data, var8, out,
-					      out_len);
+		ret = gmin_get_hardcoded_var(maindev, id->driver_data, var8,
+					     out, out_len);
+		if (!ret)
+			return 0;
 	}
 
 	/* Our variable names are ASCII by construction, but EFI names
@@ -1102,9 +1106,9 @@ static int gmin_get_config_var(struct device *maindev,
 		*out_len = ev->var.DataSize;
 		dev_info(maindev, "found EFI entry for '%s'\n", var8);
 	} else if (is_gmin) {
-		dev_warn(maindev, "Failed to find gmin variable %s\n", var8);
+		dev_info(maindev, "Failed to find EFI gmin variable %s\n", var8);
 	} else {
-		dev_warn(maindev, "Failed to find variable %s\n", var8);
+		dev_info(maindev, "Failed to find EFI variable %s\n", var8);
 	}
 
 	kfree(ev);
@@ -1123,6 +1127,8 @@ int gmin_get_var_int(struct device *dev, bool is_gmin, const char *var, int def)
 	if (!ret) {
 		val[len] = 0;
 		ret = kstrtol(val, 0, &result);
+	} else {
+		dev_info(dev, "%s: using default (%d)\n", var, def);
 	}
 
 	return ret ? def : result;
-- 
2.26.2