On Wed, Apr 29, 2015 at 03:44:37PM +0300, Jarkko Nikula wrote:
> 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@xxxxxxxxxxxxxxx>
Besides it should be squashed with the previous patch, I'm fine with
this. Mika?
> ---
> drivers/i2c/i2c-core.c | 36 +++++++++++++++++++++---------------
> 1 file changed, 21 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index 051aa3a811a8..3f25d758d83e 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;
> @@ -280,74 +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->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;
> @@ -361,6 +366,7 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
> gsb->status = status;
>
> err:
> + kfree(client);
> ACPI_FREE(ares);
> return ret;
> }
> --
> 2.1.4
>
Attachment:
signature.asc
Description: Digital signature
