[PATCH v3 29/49] Input: atmel_mxt_ts - implement debug output for messages

[PATCH v3 29/49] Input: atmel_mxt_ts - implement debug output for messages

[Jiada Wang]

From: Nick Dyer <nick.dyer@itdev.co.uk>

Add a debug switch which causes all messages from the touch controller to
be dumped to the dmesg log with a set prefix "MXT MSG:". This is used by
Atmel user-space utilities to debug touch operation. Enabling this output
does impact touch performance.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
(cherry picked from ndyer/linux/for-upstream commit 3c3fcfdd4889dfeb1c80ae8cd94a622c6342b06a)
[gdavis: Forward port and fix conflicts.]
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 47 ++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 570001131a65..7cc127a529fc 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -335,6 +335,7 @@ struct mxt_data {
 	u8 t100_aux_ampl;
 	u8 t100_aux_area;
 	u8 t100_aux_vect;
+	bool debug_enabled;
 	u8 max_reportid;
 	u32 config_crc;
 	u32 info_crc;
@@ -460,8 +461,11 @@ static bool mxt_object_readable(unsigned int type)
 
 static void mxt_dump_message(struct mxt_data *data, u8 *message)
 {
-	dev_dbg(&data->client->dev, "message: %*ph\n",
-		data->T5_msg_size, message);
+	/* debug message with prefix 'MXT MSG:' used by
+	 * Atmel user-space utilities to debug touch operation
+	 */
+	dev_dbg(&data->client->dev, "MXT MSG: %*ph\n",
+		       data->T5_msg_size, message);
 }
 
 static int mxt_wait_for_completion(struct mxt_data *data,
@@ -1214,6 +1218,7 @@ static void mxt_proc_t93_messages(struct mxt_data *data, u8 *msg)
 static int mxt_proc_message(struct mxt_data *data, u8 *message)
 {
 	u8 report_id = message[0];
+	bool dump = data->debug_enabled;
 
 	if (report_id == MXT_RPTID_NOMSG)
 		return 0;
@@ -1248,9 +1253,12 @@ static int mxt_proc_message(struct mxt_data *data, u8 *message)
 	} else if (report_id == data->T93_reportid) {
 		mxt_proc_t93_messages(data, message);
 	} else {
-		mxt_dump_message(data, message);
+		dump = true;
 	}
 
+	if (dump)
+		mxt_dump_message(data, message);
+
 	return 1;
 }
 
@@ -3522,6 +3530,36 @@ static ssize_t mxt_update_cfg_store(struct device *dev,
 	return ret;
 }
 
+static ssize_t mxt_debug_enable_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct mxt_data *data = dev_get_drvdata(dev);
+	char c;
+
+	c = data->debug_enabled ? '1' : '0';
+	return scnprintf(buf, PAGE_SIZE, "%c\n", c);
+}
+
+static ssize_t mxt_debug_enable_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct mxt_data *data = dev_get_drvdata(dev);
+	u8 i;
+	ssize_t ret;
+
+	if (kstrtou8(buf, 0, &i) == 0 && i < 2) {
+		data->debug_enabled = (i == 1);
+
+		dev_dbg(dev, "%s\n", i ? "debug enabled" : "debug disabled");
+		ret = count;
+	} else {
+		dev_dbg(dev, "debug_enabled write error\n");
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
 static DEVICE_ATTR(update_fw, S_IWUSR, NULL, mxt_update_fw_store);
 
 static struct attribute *mxt_fw_attrs[] = {
@@ -3538,6 +3576,8 @@ static DEVICE_ATTR(hw_version, S_IRUGO, mxt_hw_version_show, NULL);
 static DEVICE_ATTR(object, S_IRUGO, mxt_object_show, NULL);
 static DEVICE_ATTR(update_cfg, S_IWUSR, NULL, mxt_update_cfg_store);
 static DEVICE_ATTR(config_crc, S_IRUGO, mxt_config_crc_show, NULL);
+static DEVICE_ATTR(debug_enable, S_IWUSR | S_IRUSR, mxt_debug_enable_show,
+		   mxt_debug_enable_store);
 
 static struct attribute *mxt_attrs[] = {
 	&dev_attr_fw_version.attr,
@@ -3545,6 +3585,7 @@ static struct attribute *mxt_attrs[] = {
 	&dev_attr_object.attr,
 	&dev_attr_update_cfg.attr,
 	&dev_attr_config_crc.attr,
+	&dev_attr_debug_enable.attr,
 	NULL
 };
 
-- 
2.19.2

[PATCH v3 30/49] Input: atmel_mxt_ts - implement improved debug message interface

[Jiada Wang]

From: Nick Dyer <nick.dyer@itdev.co.uk>

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
(cherry picked from ndyer/linux/for-upstream commit 078569c13c88dcb6f8d882bfe17168587712df7d)
[gdavis: Resolve forward port conflicts due to v4.14.51 commit
	 960fe000b1d3 ("Input: atmel_mxt_ts - fix the firmware
	 update").]
Signed-off-by: George G. Davis <george_davis@mentor.com>
[gdavis: Squash fixes from Dirk Behme:
	 - Input: atmel_mxt_ts - add missing unlock in error path
	 - Input: atmel_mxt_ts - add missing unlock in error path
	 - Input: atmel_mxt_ts - call mxt_debug_msg_remove() in error path
	 - Input: atmel_mxt_ts - protect debug_v2_enabled by mutex
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
[gdavis: Squash fix from Vladimir Zapolskiy:
	 - Input: atmel_mxt_ts - simplify debug_msg binary attribute
	   handling]
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
---
Notes:
- Squash fixes from Dirk Behme:
  + Input: atmel_mxt_ts - add missing unlock in error path

    Unlock the mutex in case the function is exited in the error case.
  + Input: atmel_mxt_ts - add missing unlock in error path
  + Input: atmel_mxt_ts - protect debug_v2_enabled by mutex

    Put the modification of debug_v2_enabled into the protected section.
    Same as in mxt_debug_msg_enable().
  + Input: atmel_mxt_ts - call mxt_debug_msg_remove() in error path

    Add the missing mxt_debug_msg_remove() to the error path.
- Squash fix from Vladimir Zapolskiy:
  + Input: atmel_mxt_ts - simplify debug_msg binary attribute handling

    The change introduces several updates, but all of them are related to
    "debug_msg" binary attribute:

    * removed dynamic initialization of data->debug_msg_attr
    * removed mxt_debug_msg_write callback
    * removed wrong check in mxt_debug_msg_remove()
    * mxt_debug_msg_remove() now is not called from mxt_free_object_table()
      avoiding multiple double deallocations.

[jiada: Add NULL check for sysfs attribute debug_msg_attr]
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 194 ++++++++++++++++++++++-
 1 file changed, 192 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 7cc127a529fc..b3152aaaed63 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -242,6 +242,8 @@ enum t100_type {
 
 #define MXT_PIXELS_PER_MM	20
 
+#define DEBUG_MSG_MAX		200
+
 struct mxt_info {
 	u8 family_id;
 	u8 variant_id;
@@ -336,6 +338,11 @@ struct mxt_data {
 	u8 t100_aux_area;
 	u8 t100_aux_vect;
 	bool debug_enabled;
+	bool debug_v2_enabled;
+	u8 *debug_msg_data;
+	u16 debug_msg_count;
+	struct bin_attribute *debug_msg_attr;
+	struct mutex debug_msg_lock;
 	u8 max_reportid;
 	u32 config_crc;
 	u32 info_crc;
@@ -468,6 +475,144 @@ static void mxt_dump_message(struct mxt_data *data, u8 *message)
 		       data->T5_msg_size, message);
 }
 
+static void mxt_debug_msg_enable(struct mxt_data *data)
+{
+	struct device *dev = &data->client->dev;
+
+	if (data->debug_v2_enabled)
+		return;
+
+	mutex_lock(&data->debug_msg_lock);
+
+	data->debug_msg_data = kcalloc(DEBUG_MSG_MAX,
+				data->T5_msg_size, GFP_KERNEL);
+	if (!data->debug_msg_data) {
+		mutex_unlock(&data->debug_msg_lock);
+		return;
+	}
+
+	data->debug_v2_enabled = true;
+	mutex_unlock(&data->debug_msg_lock);
+
+	dev_dbg(dev, "Enabled message output\n");
+}
+
+static void mxt_debug_msg_disable(struct mxt_data *data)
+{
+	struct device *dev = &data->client->dev;
+
+	if (!data->debug_v2_enabled)
+		return;
+
+	mutex_lock(&data->debug_msg_lock);
+
+	data->debug_v2_enabled = false;
+
+	kfree(data->debug_msg_data);
+	data->debug_msg_data = NULL;
+	data->debug_msg_count = 0;
+	mutex_unlock(&data->debug_msg_lock);
+	dev_dbg(dev, "Disabled message output\n");
+}
+
+static void mxt_debug_msg_add(struct mxt_data *data, u8 *msg)
+{
+	struct device *dev = &data->client->dev;
+
+	mutex_lock(&data->debug_msg_lock);
+
+	if (!data->debug_msg_data) {
+		mutex_unlock(&data->debug_msg_lock);
+		dev_err(dev, "No buffer!\n");
+		return;
+	}
+
+	if (data->debug_msg_count < DEBUG_MSG_MAX) {
+		memcpy(data->debug_msg_data +
+		       data->debug_msg_count * data->T5_msg_size,
+		       msg,
+		       data->T5_msg_size);
+		data->debug_msg_count++;
+	} else {
+		dev_dbg(dev, "Discarding %u messages\n", data->debug_msg_count);
+		data->debug_msg_count = 0;
+	}
+
+	mutex_unlock(&data->debug_msg_lock);
+
+	sysfs_notify(&data->client->dev.kobj, NULL, "debug_notify");
+}
+
+static ssize_t mxt_debug_msg_read(struct file *filp, struct kobject *kobj,
+	struct bin_attribute *bin_attr, char *buf, loff_t off, size_t bytes)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct mxt_data *data = dev_get_drvdata(dev);
+	int count;
+	size_t bytes_read;
+
+	if (!data->debug_msg_data) {
+		dev_err(dev, "No buffer!\n");
+		return 0;
+	}
+
+	count = bytes / data->T5_msg_size;
+
+	if (count > DEBUG_MSG_MAX)
+		count = DEBUG_MSG_MAX;
+
+	mutex_lock(&data->debug_msg_lock);
+
+	if (count > data->debug_msg_count)
+		count = data->debug_msg_count;
+
+	bytes_read = count * data->T5_msg_size;
+
+	memcpy(buf, data->debug_msg_data, bytes_read);
+	data->debug_msg_count = 0;
+
+	mutex_unlock(&data->debug_msg_lock);
+
+	return bytes_read;
+}
+
+static struct bin_attribute debug_msg_attr = {
+	.attr = {
+		.name = "debug_msg",
+		.mode = 0444,
+	},
+	.read = mxt_debug_msg_read,
+};
+
+static int mxt_debug_msg_init(struct mxt_data *data)
+{
+	/*
+	 * Binary attribute is not used in callback, removal is done by name,
+	 * so it is safe to update a single struct bin_attribute entity
+	 */
+	debug_msg_attr.size = data->T5_msg_size * DEBUG_MSG_MAX;
+
+	if (sysfs_create_bin_file(&data->client->dev.kobj,
+				  &debug_msg_attr) < 0) {
+		dev_err(&data->client->dev, "Failed to create %s\n",
+			debug_msg_attr.attr.name);
+		return -EINVAL;
+	}
+
+	data->debug_msg_attr = &debug_msg_attr;
+
+	return 0;
+}
+
+static void mxt_debug_msg_remove(struct mxt_data *data)
+{
+	if (data->debug_msg_attr) {
+		sysfs_remove_bin_file(&data->client->dev.kobj,
+				      data->debug_msg_attr);
+		data->debug_msg_attr = NULL;
+	}
+}
+
 static int mxt_wait_for_completion(struct mxt_data *data,
 				   struct completion *comp,
 				   unsigned int timeout_ms)
@@ -1259,6 +1404,9 @@ static int mxt_proc_message(struct mxt_data *data, u8 *message)
 	if (dump)
 		mxt_dump_message(data, message);
 
+	if (data->debug_v2_enabled)
+		mxt_debug_msg_add(data, message);
+
 	return 1;
 }
 
@@ -2677,6 +2825,10 @@ static int mxt_initialize(struct mxt_data *data)
 	if (error)
 		return error;
 
+	error = mxt_debug_msg_init(data);
+	if (error)
+		goto err_free_sysfs;
+
 	if (data->cfg_name) {
 		error = request_firmware_nowait(THIS_MODULE, true,
 						data->cfg_name,
@@ -2686,16 +2838,18 @@ static int mxt_initialize(struct mxt_data *data)
 		if (error) {
 			dev_err(&client->dev, "Failed to invoke firmware loader: %d\n",
 				error);
-			goto err_free_sysfs;
+			goto err_free_dbg_msg;
 		}
 	} else {
 		error = mxt_configure_objects(data, NULL);
 		if (error)
-			goto err_free_sysfs;
+			goto err_free_dbg_msg;
 	}
 
 	return 0;
 
+err_free_dbg_msg:
+	mxt_debug_msg_remove(data);
 err_free_sysfs:
 	mxt_sysfs_remove(data);
 	return error;
@@ -3357,6 +3511,7 @@ static int mxt_enter_bootloader(struct mxt_data *data)
 			return ret;
 
 		data->in_bootloader = true;
+		mxt_debug_msg_remove(data);
 		mxt_sysfs_remove(data);
 		mxt_free_input_device(data);
 		mxt_free_object_table(data);
@@ -3540,6 +3695,34 @@ static ssize_t mxt_debug_enable_show(struct device *dev,
 	return scnprintf(buf, PAGE_SIZE, "%c\n", c);
 }
 
+static ssize_t mxt_debug_notify_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "0\n");
+}
+
+static ssize_t mxt_debug_v2_enable_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct mxt_data *data = dev_get_drvdata(dev);
+	u8 i;
+	ssize_t ret;
+
+	if (kstrtou8(buf, 0, &i) == 0 && i < 2) {
+		if (i == 1)
+			mxt_debug_msg_enable(data);
+		else
+			mxt_debug_msg_disable(data);
+
+		ret = count;
+	} else {
+		dev_dbg(dev, "debug_enabled write error\n");
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
 static ssize_t mxt_debug_enable_store(struct device *dev,
 	struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -3578,6 +3761,9 @@ static DEVICE_ATTR(update_cfg, S_IWUSR, NULL, mxt_update_cfg_store);
 static DEVICE_ATTR(config_crc, S_IRUGO, mxt_config_crc_show, NULL);
 static DEVICE_ATTR(debug_enable, S_IWUSR | S_IRUSR, mxt_debug_enable_show,
 		   mxt_debug_enable_store);
+static DEVICE_ATTR(debug_v2_enable, S_IWUSR | S_IRUSR, NULL,
+		   mxt_debug_v2_enable_store);
+static DEVICE_ATTR(debug_notify, S_IRUGO, mxt_debug_notify_show, NULL);
 
 static struct attribute *mxt_attrs[] = {
 	&dev_attr_fw_version.attr,
@@ -3586,6 +3772,8 @@ static struct attribute *mxt_attrs[] = {
 	&dev_attr_update_cfg.attr,
 	&dev_attr_config_crc.attr,
 	&dev_attr_debug_enable.attr,
+	&dev_attr_debug_v2_enable.attr,
+	&dev_attr_debug_notify.attr,
 	NULL
 };
 
@@ -3875,6 +4063,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	init_completion(&data->chg_completion);
 	init_completion(&data->reset_completion);
 	init_completion(&data->crc_completion);
+	mutex_init(&data->debug_msg_lock);
 
 	data->suspend_mode = dmi_check_system(chromebook_T9_suspend_dmi) ?
 		MXT_SUSPEND_T9_CTRL : MXT_SUSPEND_DEEP_SLEEP;
@@ -3933,6 +4122,7 @@ static int mxt_remove(struct i2c_client *client)
 
 	disable_irq(data->irq);
 	sysfs_remove_group(&client->dev.kobj, &mxt_fw_attr_group);
+	mxt_debug_msg_remove(data);
 	mxt_sysfs_remove(data);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
-- 
2.19.2

[PATCH v3 31/49] Input: atmel_mxt_ts - eliminate data->raw_info_block

[Jiada Wang]

Dynamically allocated in mxt_read_info_block() buffer buf is assigned
both to data->info and data->raw_info_block, having both data->info
and data->raw_info_block is redundant and confusing.

This patch eliminates data->raw_info_block.

Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index b3152aaaed63..560fe8a3bf62 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -323,7 +323,6 @@ struct mxt_data {
 	char phys[64];		/* device physical location */
 	struct mxt_object *object_table;
 	struct mxt_info *info;
-	void *raw_info_block;
 	unsigned int irq;
 	unsigned int max_x;
 	unsigned int max_y;
@@ -2070,9 +2069,8 @@ static void mxt_free_object_table(struct mxt_data *data)
 	v4l2_device_unregister(&data->dbg.v4l2);
 #endif
 	data->object_table = NULL;
+	kfree(data->info);
 	data->info = NULL;
-	kfree(data->raw_info_block);
-	data->raw_info_block = NULL;
 	kfree(data->msg_buf);
 	data->msg_buf = NULL;
 	data->T5_address = 0;
@@ -2241,7 +2239,7 @@ static int mxt_read_info_block(struct mxt_data *data)
 	u8 *crc_ptr;
 
 	/* If info block already allocated, free it */
-	if (data->raw_info_block)
+	if (data->info)
 		mxt_free_object_table(data);
 
 	/* Read 7-byte ID information block starting at address 0 */
@@ -2292,7 +2290,6 @@ static int mxt_read_info_block(struct mxt_data *data)
 		goto err_free_mem;
 	}
 
-	data->raw_info_block = id_buf;
 	data->info = (struct mxt_info *)id_buf;
 
 	dev_info(&client->dev,
-- 
2.19.2

[PATCH v3 32/49] Input: atmel_mxt_ts - Change call-points of mxt_free_* functions

[Jiada Wang]

From: Kautuk Consul <kautuk_consul@mentor.com>

Revamping the code to call mxt_free_object_table and mxt_free_input_device
functions only in the following scenarios and code paths:
1) The error path of the mxt_probe() entry point
2) The mxt_remove de-init path entry point
3) All paths which definitely expect to populate the object table
   like:
   - the mxt_update_fw_store path which first calls
     mxt_load_fw and then resorts to calling mxt_initialize itself.
   - the mxt_read_info_block function which attempts to fill in the
     object table itself as the main non-error part of the logic.
4) All paths in the code expected to definitely allocate and register
   the input device such as:
   - the mxt_update_fw_store path which first calls
     mxt_load_fw and then resorts to calling mxt_initialize itself.
   - the mxt_update_cfg_store function which will call
     mxt_configure_objects.

Signed-off-by: Kautuk Consul <kautuk_consul@mentor.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 560fe8a3bf62..e441eab8b201 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -3339,21 +3339,21 @@ static int mxt_configure_objects(struct mxt_data *data,
 	error = mxt_init_t7_power_cfg(data);
 	if (error) {
 		dev_err(dev, "Failed to initialize power cfg\n");
-		goto err_free_object_table;
+		return error;
 	}
 
 	if (cfg) {
 		error = mxt_update_cfg(data, cfg);
 		if (error) {
 			dev_warn(dev, "Error %d updating config\n", error);
-			goto err_free_object_table;
+			return error;
 		}
 	}
 
 	if (data->multitouch) {
 		error = mxt_initialize_input_device(data);
 		if (error)
-			goto err_free_object_table;
+			return error;
 	} else {
 		dev_warn(dev, "No touch object detected\n");
 	}
@@ -3361,10 +3361,6 @@ static int mxt_configure_objects(struct mxt_data *data,
 	mxt_debug_init(data);
 
 	return 0;
-
-err_free_object_table:
-	mxt_free_object_table(data);
-	return error;
 }
 
 /* Configuration crc check sum is returned as hex xxxxxx */
@@ -4101,16 +4097,21 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	error = mxt_initialize(data);
 	if (error)
-		return error;
+		goto err_free_object;
 
 	error = sysfs_create_group(&client->dev.kobj, &mxt_fw_attr_group);
 	if (error) {
 		dev_err(&client->dev, "Failure %d creating fw sysfs group\n",
 			error);
-		return error;
+		goto err_free_object;
 	}
 
 	return 0;
+
+err_free_object:
+	mxt_free_input_device(data);
+	mxt_free_object_table(data);
+	return error;
 }
 
 static int mxt_remove(struct i2c_client *client)
-- 
2.19.2

[PATCH v3 33/49] Input: atmel_mxt_ts - rely on calculated_crc rather than file config_crc

[Jiada Wang]

From: Kautuk Consul <kautuk_consul@mentor.com>

We now prefer to rely on the calculated CRC and not on the CRC stored in
the file.

The new logic is as follows:
1) stored CRC of file != calculated CRC of file, then refuse the possible
   corrupted file
2) calculated CRC of file != CRC of configuration in controller, then
   update configuration in controller
3) calculated CRC of file == CRC of configuration in controller, then
   ignore configuration file

Signed-off-by: Kautuk Consul <kautuk_consul@mentor.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 65 +++++++++++++-----------
 1 file changed, 36 insertions(+), 29 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index e441eab8b201..bdc5088baea8 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -1908,7 +1908,7 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw)
 	int ret;
 	int offset;
 	int i;
-	u32 info_crc, config_crc, calculated_crc;
+	u32 info_crc, config_crc, calculated_crc = 0;
 	u16 crc_start = 0;
 
 	/* Make zero terminated copy of the OBP_RAW file */
@@ -1971,30 +1971,6 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw)
 	}
 	cfg.raw_pos += offset;
 
-	/*
-	 * The Info Block CRC is calculated over mxt_info and the object
-	 * table. If it does not match then we are trying to load the
-	 * configuration from a different chip or firmware version, so
-	 * the configuration CRC is invalid anyway.
-	 */
-	if (info_crc == data->info_crc) {
-		if (config_crc == 0 || data->config_crc == 0) {
-			dev_info(dev, "CRC zero, attempting to apply config\n");
-		} else if (config_crc == data->config_crc) {
-			dev_dbg(dev, "Config CRC 0x%06X: OK\n",
-				 data->config_crc);
-			ret = 0;
-			goto release_raw;
-		} else {
-			dev_info(dev, "Config CRC 0x%06X: does not match file 0x%06X\n",
-				 data->config_crc, config_crc);
-		}
-	} else {
-		dev_warn(dev,
-			 "Warning: Info CRC error - device=0x%06X file=0x%06X\n",
-			 data->info_crc, info_crc);
-	}
-
 	/* Malloc memory to store configuration */
 	cfg.start_ofs = MXT_OBJECT_START +
 			data->info->object_num * sizeof(struct mxt_object) +
@@ -2018,14 +1994,45 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw)
 	else
 		dev_warn(dev, "Could not find CRC start\n");
 
-	if (crc_start > cfg.start_ofs) {
+	if (crc_start > cfg.start_ofs)
 		calculated_crc = mxt_calculate_crc(cfg.mem,
 						   crc_start - cfg.start_ofs,
 						   cfg.mem_size);
 
-		if (config_crc > 0 && config_crc != calculated_crc)
-			dev_warn(dev, "Config CRC in file inconsistent, calculated=%06X, file=%06X\n",
-				 calculated_crc, config_crc);
+	/* If the CRC stored in the file is not the same as what
+	 * was calculated by mxt_calculate_crc, this means we
+	 * have to refuse the config file and abort download.
+	 */
+	if (config_crc != calculated_crc) {
+		dev_warn(dev,
+			 "Config CRC in file inconsistent, calculated=%06X, file=%06X\n",
+			 calculated_crc, config_crc);
+		ret = 0;
+		goto release_mem;
+	}
+
+	/*
+	 * The Info Block CRC is calculated over mxt_info and the object
+	 * table. If it does not match then we are trying to load the
+	 * configuration from a different chip or firmware version, so
+	 * the configuration CRC is invalid anyway.
+	 */
+	if (info_crc == data->info_crc) {
+		if (config_crc == 0 || data->config_crc == 0) {
+			dev_info(dev, "CRC zero, attempting to apply config\n");
+		} else if (config_crc == data->config_crc) {
+			dev_dbg(dev, "Config CRC 0x%06X: OK\n",
+				data->config_crc);
+			ret = 0;
+			goto release_mem;
+		} else {
+			dev_info(dev, "Config CRC 0x%06X: does not match file 0x%06X\n",
+				 data->config_crc, config_crc);
+		}
+	} else {
+		dev_warn(dev,
+			 "Warning: Info CRC error - device=0x%06X file=0x%06X\n",
+			 data->info_crc, info_crc);
 	}
 
 	ret = mxt_upload_cfg_mem(data, &cfg);
-- 
2.19.2