Commit Graph

11 Commits

Author SHA1 Message Date
Michael Zaidman
1edfae51d5 HID: ft260: support i2c writes larger than HID report size
To support longer than one HID report size write, the driver splits a
single i2c message data payload into multiple i2c messages of HID report
size. However, it does not replicate the offset bytes within the EEPROM
chip in every consequent HID report because it is not and should not be
aware of the EEPROM type. It breaks the i2c write message integrity and
causes the EEPROM device not to acknowledge the second HID report keeping
the i2c bus busy until the ft260 controller reports failure.

This patch preserves the i2c write message integrity by manipulating the
i2c flag bits across multiple HID reports to be seen by the EEPROM device
as a single i2c write transfer.

Before:

$ sudo ./i2cperf -f 2 -o 2 -s 64 -r 0-0xff 13 0x51 -S
Error: Sending messages failed: Input/output error

[  +3.667741] ft260_i2c_write: rep 0xde addr 0x51 off 0 len 60 d[0] 0x0
[  +0.007330] ft260_hid_output_report_check_status: wait 6400 usec, len 64
[  +0.000203] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.000001] ft260_i2c_write: rep 0xd1 addr 0x51 off 60 len 6 d[0] 0x0
[  +0.002337] ft260_hid_output_report_check_status: wait 1000 usec, len 10
[  +0.000157] ft260_xfer_status: bus_status 0x2e, clock 100
[  +0.000241] ft260_i2c_reset: done
[  +0.000003] ft260_i2c_write: failed to start transfer, ret -5

After:

$ sudo ./i2cperf -f 2 -o 2 -s 128 -r 0-0xff 13 0x51 -S

  Fill block with increment via i2ctransfer by chunks
  -------------------------------------------------------------------
  data rate(bps)  efficiency(%)  data size(B)  total IOs   IO size(B)
  -------------------------------------------------------------------
  71260           86             256           2           128

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Tested-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2022-11-11 11:09:35 +01:00
Michael Zaidman
6fca5e3f55 HID: ft260: improve i2c write performance
The patch improves the I2C write performance by 20 - 30 percent by
revising the sleep time in the ft260_hid_output_report_check_status()
in the following ways:

1. Reduce the wait time and start to poll earlier.

Sending a large amount of data at a low I2C clock rate saturates the
internal FT260 buffer and causes hiccups in status readiness, as shown
below in the log fragment. Aligning the status check wait time to the
worst case significantly reduces the write performance.

[Oct22 10:28] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.005296] ft260_xfer_status: bus_status 0x20, clock 100
[  +0.013460] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.003244] ft260_hid_output_report_check_status: wait 1920 usec, len 38
[  +0.000190] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.015324] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.003491] ft260_hid_output_report_check_status: wait 1920 usec, len 38
[  +0.000202] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.016047] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.002768] ft260_hid_output_report_check_status: wait 1920 usec, len 38
[  +0.000150] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.011389] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.003467] ft260_hid_output_report_check_status: wait 1920 usec, len 38
[  +0.000191] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000172] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000131] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000241] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000233] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000190] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000196] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.011314] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0
[  +0.003334] ft260_hid_output_report_check_status: wait 1920 usec, len 38
[  +0.000227] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000204] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000198] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000147] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.011060] ft260_i2c_write: rep 0xd8 addr 0x51 off 0 len 34 d[0] 0x0

  Before:
    $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S

      Fill block with increment via i2ctransfer by chunks
      -------------------------------------------------------------------
      data rate(bps)  efficiency(%)  data size(B)  total IOs   IO size(B)
      -------------------------------------------------------------------
      40510           80             256           8           32

  After:
    $ sudo ./i2cperf -f 2 -o 2 -s 32 -r 0-0xff 13 0x51 -S

      Fill block with increment via i2ctransfer by chunks
      -------------------------------------------------------------------
      data rate(bps)  efficiency(%)  data size(B)  total IOs   IO size(B)
      -------------------------------------------------------------------
      52584           80             256           8           32

2. Do not sleep if the estimated I2C transfer time is below 2 ms since
   the first xfer status query frequently takes around 1.5 ms, and the
   following status queries take about 200us on average. So we usually
   return from the routine after the first 1 - 3 status checks.

[Oct22 11:14] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0
[  +0.004270] ft260_xfer_status: bus_status 0x20, clock 100
[  +0.013889] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0
[  +0.000856] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000138] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.013352] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0
[  +0.001501] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000177] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.014477] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0
[  +0.001377] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000233] ft260_xfer_status: bus_status 0x41, clock 100
[  +0.000191] ft260_xfer_status: bus_status 0x40, clock 100
[  +0.013197] ft260_i2c_write: rep 0xd4 addr 0x51 off 0 len 18 d[0] 0x0

  Before:
    $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S

      Fill block with increment via i2ctransfer by chunks
      -------------------------------------------------------------------
      data rate(bps)  efficiency(%)  data size(B)  total IOs   IO size(B)
      -------------------------------------------------------------------
      28826           73             256           16          16

  After:
    $ sudo ./i2cperf -f 2 -o 2 -s 16 -r 0-0xff 13 0x51 -S

      Fill block with increment via i2ctransfer by chunks
      -------------------------------------------------------------------
      data rate(bps)  efficiency(%)  data size(B)  total IOs   IO size(B)
      -------------------------------------------------------------------
      45138           73             256           16          16

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Tested-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2022-11-11 11:09:35 +01:00
Michael Zaidman
f45d50ede6 HID: ft260: ft260_xfer_status routine cleanup
After clarifying with FTDI's support, it turned out that the error
condition (bit 1) in byte 1 of the i2c status HID report is a status
bit reflecting all error conditions. When bits 2, 3, or 4 are raised
to 1, bit 1 is set to 1 also. Since the ft260_xfer_status routine tests
the error condition bit and exits in the case of an error, the program
flow never reaches the conditional expressions for 2, 3, and 4 bits when
any of them indicates an error state. Though these expressions are never
evaluated to true, they are checked several times per IO, increasing the
ft260_xfer_status polling cycle duration.

The patch removes the conditional expressions for 2, 3, and 4 bits in
byte 1 of the i2c status HID report.

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Tested-by: Guillaume Champagne <champagne.guillaume.c@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2022-11-11 11:09:35 +01:00
Greg Kroah-Hartman
93020953d0 HID: check for valid USB device for many HID drivers
Many HID drivers assume that the HID device assigned to them is a USB
device as that was the only way HID devices used to be able to be
created in Linux.  However, with the additional ways that HID devices
can be created for many different bus types, that is no longer true, so
properly check that we have a USB device associated with the HID device
before allowing a driver that makes this assumption to claim it.

Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Michael Zaidman <michael.zaidman@gmail.com>
Cc: Stefan Achatz <erazor_de@users.sourceforge.net>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: linux-input@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
[bentiss: amended for thrustmater.c hunk to apply]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211201183503.2373082-3-gregkh@linuxfoundation.org
2021-12-02 15:36:18 +01:00
Michael Zaidman
a94f61e63f HID: ft260: fix i2c probing for hwmon devices
The below scenario causes the kernel NULL pointer dereference failure:
1. sudo insmod hid-ft260.ko
2. sudo modprobe lm75
3. unplug USB hid-ft260
4. plug USB hid-ft260

[  +0.000006] Call Trace:
[  +0.000004]  __i2c_smbus_xfer.part.0+0xd1/0x310
[  +0.000007]  ? ft260_smbus_write+0x140/0x140 [hid_ft260]
[  +0.000005]  __i2c_smbus_xfer+0x2b/0x80
[  +0.000004]  i2c_smbus_xfer+0x61/0xf0
[  +0.000005]  i2c_default_probe+0xf9/0x130
[  +0.000004]  i2c_detect_address+0x84/0x160
[  +0.000004]  ? kmem_cache_alloc_trace+0xf6/0x200
[  +0.000009]  ? i2c_detect.isra.0+0x69/0x130
[  +0.000005]  i2c_detect.isra.0+0xbf/0x130
[  +0.000004]  ? __process_new_driver+0x30/0x30
[  +0.000004]  __process_new_adapter+0x18/0x20
[  +0.000004]  bus_for_each_drv+0x84/0xd0
[  +0.000003]  i2c_register_adapter+0x1e4/0x400
[  +0.000005]  i2c_add_adapter+0x5c/0x80
[  +0.000004]  ft260_probe.cold+0x222/0x2e2 [hid_ft260]
[  +0.000006]  hid_device_probe+0x10e/0x170 [hid]
[  +0.000009]  really_probe+0xff/0x460
[  +0.000004]  driver_probe_device+0xe9/0x160
[  +0.000003]  __device_attach_driver+0x71/0xd0
[  +0.000004]  ? driver_allows_async_probing+0x50/0x50
[  +0.000004]  bus_for_each_drv+0x84/0xd0
[  +0.000002]  __device_attach+0xde/0x1e0
[  +0.000004]  device_initial_probe+0x13/0x20
[  +0.000004]  bus_probe_device+0x8f/0xa0
[  +0.000003]  device_add+0x333/0x5f0

It happened when i2c core probed for the devices associated with the lm75
driver by invoking 2c_detect()-->..-->ft260_smbus_write() from within the
ft260_probe before setting the adapter data with i2c_set_adapdata().

Moving the i2c_set_adapdata() before i2c_add_adapter() fixed the failure.

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Signed-off-by: Germain Hebert <germain.hebert@ca.abb.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-11-19 15:46:06 +01:00
Michael Zaidman
db8d3a2127 HID: ft260: fix device removal due to USB disconnect
This commit fixes a functional regression introduced by the commit 82f09a637d
("HID: ft260: improve error handling of ft260_hid_feature_report_get()")
when upon USB disconnect, the FTDI FT260 i2c device is still available within
the /dev folder.

In my company's product, where the host USB to FT260 USB connection is
hard-wired in the PCB, the issue is not reproducible. To reproduce it, I used
the VirtualBox Ubuntu 20.04 VM and the UMFT260EV1A development module for the
FTDI FT260 chip:

Plug the UMFT260EV1A module into a USB port and attach it to VM.

The VM shows 2 i2c devices under the /dev:
    michael@michael-VirtualBox:~$ ls /dev/i2c-*
    /dev/i2c-0  /dev/i2c-1

The i2c-0 is not related to the FTDI FT260:
    michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-0/name
    SMBus PIIX4 adapter at 4100

The i2c-1 is created by hid-ft260.ko:
    michael@michael-VirtualBox:~$ cat /sys/bus/i2c/devices/i2c-1/name
    FT260 usb-i2c bridge on hidraw1

Now, detach the FTDI FT260 USB device from VM. We expect the /dev/i2c-1
to disappear, but it's still here:
    michael@michael-VirtualBox:~$ ls /dev/i2c-*
    /dev/i2c-0  /dev/i2c-1

And the kernel log shows:
    [  +0.001202] usb 2-2: USB disconnect, device number 3
    [  +0.000109] ft260 0003:0403:6030.0002: failed to retrieve system status
    [  +0.000316] ft260 0003:0403:6030.0003: failed to retrieve system status

It happens because the commit 82f09a637d changed the ft260_get_system_config()
return logic. This caused the ft260_is_interface_enabled() to exit with error
upon the FT260 device USB disconnect, which in turn, aborted the ft260_remove()
before deleting the FT260 i2c device and cleaning its sysfs stuff.

This commit restores the FT260 USB removal functionality and improves the
ft260_is_interface_enabled() code to handle correctly all chip modes defined
by the device interface configuration pins DCNF0 and DCNF1.

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Acked-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-07-29 12:38:32 +02:00
Michael Zaidman
9f59efcd51 HID: ft260: fix format type warning in ft260_word_show()
Fixes: 6a82582d9f ("HID: ft260: add usb hid to i2c host bridge driver")

Fix warning reported by static analysis when built with W=1 for arm64 by
clang version 13.0.0

>> drivers/hid/hid-ft260.c:794:44: warning: format specifies type 'short' but
   the argument has type 'int' [-Wformat]
           return scnprintf(buf, PAGE_SIZE, "%hi\n", le16_to_cpu(*field));
                                             ~~~     ^~~~~~~~~~~~~~~~~~~
                                             %i
   include/linux/byteorder/generic.h:91:21: note: expanded from
                                            macro 'le16_to_cpu'
   #define le16_to_cpu __le16_to_cpu
                       ^
   include/uapi/linux/byteorder/big_endian.h:36:26: note: expanded from
                                                    macro '__le16_to_cpu'
   #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/uapi/linux/swab.h:105:2: note: expanded from macro '__swab16'
           (__builtin_constant_p((__u16)(x)) ?     \
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Any sprintf style use of %h or %hi for a sub-int sized value isn't useful
since integer promotion is done on the value anyway. So, use %d instead.

https://lore.kernel.org/lkml/CAHk-=wgoxnmsj8GEVFJSvTwdnWm8wVJthefNk2n6+4TC=20e0Q@mail.gmail.com/

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-07-27 12:22:16 +02:00
Michael Zaidman
82f09a637d HID: ft260: improve error handling of ft260_hid_feature_report_get()
The ft260_hid_feature_report_get() checks if the return size matches the
requested size. But the function can also fail with at least -ENOMEM.  Add the
< 0 checks.

In ft260_hid_feature_report_get(), do not do the memcpy to the caller's buffer
if there is an error.

Fixes: 6a82582d9f ("HID: ft260: add usb hid to i2c host bridge driver")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-05-27 15:40:34 +02:00
Michael Zaidman
b45ef5db7b HID: ft260: check data size in ft260_smbus_write()
The SMbus block transaction limits the number of bytes transferred to 32,
but nothing prevents a user from specifying via ioctl a larger data size
than the ft260 can handle in a single transfer.

i2cdev_ioctl_smbus()
   --> i2c_smbus_xfer
       --> __i2c_smbus_xfer
           --> ft260_smbus_xfer
               --> ft260_smbus_write

This patch adds data size checking in the ft260_smbus_write().

Fixes: 98189a0adfa0 ("HID: ft260: add usb hid to i2c host bridge driver")
Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-05-05 14:32:46 +02:00
Dan Carpenter
2076b7bdc5 HID: ft260: fix an error message in ft260_i2c_write_read()
The "len" variable is uninitialize.

Fixes: 6a82582d9f ("HID: ft260: add usb hid to i2c host bridge driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-03-19 14:26:16 +01:00
Michael Zaidman
6a82582d9f HID: ft260: add usb hid to i2c host bridge driver
The FTDI FT260 chip implements USB to I2C/UART bridges through two
USB HID class interfaces. The first - for I2C, and the second for UART.
Each interface is independent, and the kernel detects it as a separate
USB hidraw device.

This commit adds I2C host adapter support.

Signed-off-by: Michael Zaidman <michael.zaidman@gmail.com>
Tested-by: Aaron Jones (FTDI-UK) <aaron.jones@ftdichip.com
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2021-03-16 08:22:54 +01:00