linux/drivers/input/rmi4
Hans Verkuil a284e11c37 Input: synaptics-rmi4 - don't increment rmiaddr for SMBus transfers
This increment of rmi_smbus in rmi_smb_read/write_block() causes
garbage to be read/written.

The first read of SMB_MAX_COUNT bytes is fine, but after that
it is nonsense. Trial-and-error showed that by dropping the
increment of rmiaddr everything is fine and the F54 function
properly works.

I tried a hack with rmi_smb_write_block() as well (writing to the
same F54 touchpad data area, then reading it back), and that
suggests that there too the rmiaddr increment has to be dropped.
It makes sense that if it has to be dropped for read, then it has
to be dropped for write as well.

It looks like the initial work with F54 was done using i2c, not smbus,
and it seems nobody ever tested F54 with smbus. The other functions
all read/write less than SMB_MAX_COUNT as far as I can tell, so this
issue was never noticed with non-F54 functions.

With this change I can read out the touchpad data correctly on my
Lenovo X1 Carbon 6th Gen laptop.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Link: https://lore.kernel.org/r/8dd22e21-4933-8e9c-a696-d281872c8de7@xs4all.nl
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2019-12-04 17:58:16 -08:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rmi_2d_sensor.c Input: synaptics-rmi4 - remove the exporting of rmi_2d_sensor_set_input_params 2019-07-24 12:58:11 +03:00
rmi_2d_sensor.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_bus.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_bus.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_driver.c Input: synaptics-rmi4 - avoid processing unknown IRQs 2019-10-11 17:24:45 -07:00
rmi_driver.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f01.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f03.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f11.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f12.c Linux 5.2 2019-07-15 09:42:32 -07:00
rmi_f30.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f34.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f34.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_f34v7.c Input: synaptics-rmi4 - re-enable IRQs in f34v7_do_reflash 2019-12-04 17:58:16 -08:00
rmi_f54.c Input: synaptics-rmi4 - fix various V4L2 compliance problems in F54 2019-11-22 16:21:52 -08:00
rmi_f55.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_i2c.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rmi_smbus.c Input: synaptics-rmi4 - don't increment rmiaddr for SMBus transfers 2019-12-04 17:58:16 -08:00
rmi_spi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00