i2c: core: Reduce stack size of acpi_i2c_space_handler()
sizeof(struct i2c_client) is 1088 bytes on a CONFIG_X86_64=y build and
produces following warning when CONFIG_FRAME_WARN is set to 1024:
drivers/i2c/i2c-core.c: In function ‘acpi_i2c_space_handler’:
drivers/i2c/i2c-core.c:367:1: warning: the frame size of 1152 bytes is
larger than 1024 bytes [-Wframe-larger-than=]
This is not critical given that kernel stack is 16 kB on x86_64 but lets
reduce the stack usage by allocating the struct i2c_client from the heap.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index c007d39..96771ea 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -258,7 +258,7 @@
struct acpi_connection_info *info = &data->info;
struct acpi_resource_i2c_serialbus *sb;
struct i2c_adapter *adapter = data->adapter;
- struct i2c_client client;
+ struct i2c_client *client;
struct acpi_resource *ares;
u32 accessor_type = function >> 16;
u8 action = function & ACPI_IO_MASK;
@@ -269,6 +269,12 @@
if (ACPI_FAILURE(ret))
return ret;
+ client = kzalloc(sizeof(*client), GFP_KERNEL);
+ if (!client) {
+ ret = AE_NO_MEMORY;
+ goto err;
+ }
+
if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
ret = AE_BAD_PARAMETER;
goto err;
@@ -280,75 +286,73 @@
goto err;
}
- memset(&client, 0, sizeof(client));
- client.adapter = adapter;
- client.addr = sb->slave_address;
- client.flags = 0;
+ client->adapter = adapter;
+ client->addr = sb->slave_address;
if (sb->access_mode == ACPI_I2C_10BIT_MODE)
- client.flags |= I2C_CLIENT_TEN;
+ client->flags |= I2C_CLIENT_TEN;
switch (accessor_type) {
case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
if (action == ACPI_READ) {
- status = i2c_smbus_read_byte(&client);
+ status = i2c_smbus_read_byte(client);
if (status >= 0) {
gsb->bdata = status;
status = 0;
}
} else {
- status = i2c_smbus_write_byte(&client, gsb->bdata);
+ status = i2c_smbus_write_byte(client, gsb->bdata);
}
break;
case ACPI_GSB_ACCESS_ATTRIB_BYTE:
if (action == ACPI_READ) {
- status = i2c_smbus_read_byte_data(&client, command);
+ status = i2c_smbus_read_byte_data(client, command);
if (status >= 0) {
gsb->bdata = status;
status = 0;
}
} else {
- status = i2c_smbus_write_byte_data(&client, command,
+ status = i2c_smbus_write_byte_data(client, command,
gsb->bdata);
}
break;
case ACPI_GSB_ACCESS_ATTRIB_WORD:
if (action == ACPI_READ) {
- status = i2c_smbus_read_word_data(&client, command);
+ status = i2c_smbus_read_word_data(client, command);
if (status >= 0) {
gsb->wdata = status;
status = 0;
}
} else {
- status = i2c_smbus_write_word_data(&client, command,
+ status = i2c_smbus_write_word_data(client, command,
gsb->wdata);
}
break;
case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
if (action == ACPI_READ) {
- status = i2c_smbus_read_block_data(&client, command,
+ status = i2c_smbus_read_block_data(client, command,
gsb->data);
if (status >= 0) {
gsb->len = status;
status = 0;
}
} else {
- status = i2c_smbus_write_block_data(&client, command,
+ status = i2c_smbus_write_block_data(client, command,
gsb->len, gsb->data);
}
break;
case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
if (action == ACPI_READ) {
- status = acpi_gsb_i2c_read_bytes(&client, command,
+ status = acpi_gsb_i2c_read_bytes(client, command,
gsb->data, info->access_length);
if (status > 0)
status = 0;
} else {
- status = acpi_gsb_i2c_write_bytes(&client, command,
+ status = acpi_gsb_i2c_write_bytes(client, command,
gsb->data, info->access_length);
}
break;
@@ -362,6 +366,7 @@
gsb->status = status;
err:
+ kfree(client);
ACPI_FREE(ares);
return ret;
}