From 7ef85f5fdd081b982d43b95b06272f8646a98818 Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Wed, 20 May 2015 16:36:52 +0300 Subject: [PATCH] i2c: core: Reduce stack size of acpi_i2c_space_handler() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Acked-by: Mika Westerberg Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core.c | 37 +++++++++++++++++++++---------------- 1 file changed, 21 insertions(+), 16 deletions(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index c007d3929da5..96771eaa923e 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -258,7 +258,7 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, 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 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, 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 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, 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 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command, gsb->status = status; err: + kfree(client); ACPI_FREE(ares); return ret; } -- 2.39.5