Re: [PATCH v2] Input: synaptics-rmi4: Fix register descriptor subpacket map construction

From: Dmitry Torokhov
Date: Mon Aug 22 2016 - 17:19:24 EST


On Mon, Aug 22, 2016 at 09:58:57AM -0700, Andrew Duggan wrote:
> From: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
>
> The map_offset variable is specific to the register and needs to be reset
> in the loop. Otherwise, subsequent register's subpacket maps will have
> their bits set at the wrong index.
>
> Signed-off-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
> Tested-by: Nitin Chaudhary <nitinchaudhary1289@xxxxxxxxx>
> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx


Applied, thank you.

> ---
> In rmi_f12_read_sensor_tuning() we call rmi_register_desc_has_subpacket()
> to check the subpacket map to make sure a subpacket exists to ensure that
> the buffer contains the correct data. It happened that on my the test
> devices the register we were checking was also the first register. This
> issues showed up on newer devices where F12 CTRL 8 is not teh first control
> register.
>
> V2 moves map_offset closer to the do/while loop.
>
> Thanks,
> Andrew
>
> drivers/input/rmi4/rmi_driver.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/rmi4/rmi_driver.c b/drivers/input/rmi4/rmi_driver.c
> index 2b6b97e..00f9ad9 100644
> --- a/drivers/input/rmi4/rmi_driver.c
> +++ b/drivers/input/rmi4/rmi_driver.c
> @@ -553,7 +553,6 @@ int rmi_read_register_desc(struct rmi_device *d, u16 addr,
> goto free_struct_buff;
>
> reg = find_first_bit(rdesc->presense_map, RMI_REG_DESC_PRESENSE_BITS);
> - map_offset = 0;
> for (i = 0; i < rdesc->num_registers; i++) {
> struct rmi_register_desc_item *item = &rdesc->registers[i];
> int reg_size = struct_buf[offset];
> @@ -576,6 +575,8 @@ int rmi_read_register_desc(struct rmi_device *d, u16 addr,
> item->reg = reg;
> item->reg_size = reg_size;
>
> + map_offset = 0;
> +
> do {
> for (b = 0; b < 7; b++) {
> if (struct_buf[offset] & (0x1 << b))
> --
> 2.7.4
>

--
Dmitry