linux.git/drivers/i2c/busses, branch v4.9

Revert "i2c: octeon: thunderx: Limit register access retries"

2016-11-29T19:04:21+00:00

This reverts commit 70121f7f3725 ("i2c: octeon: thunderx: Limit register access retries").
Using readq_poll_timeout instead of __raw_readq triggers the following
debug warning:

[   78.871568] ipmi_ssif: Trying hotmod-specified SSIF interface at i2c address 0x12, adapter Cavium ThunderX i2c adapter at 0000:01:09.4, slave address 0x0
[   78.886107] do not call blocking ops when !TASK_RUNNING; state=2 set at [] prepare_to_wait_event+0x58/0x10c
[   78.897436] ------------[ cut here ]------------
[   78.902050] WARNING: CPU: 6 PID: 2235 at kernel/sched/core.c:7718 __might_sleep+0x80/0x88

[...]

[   79.133553] [] __might_sleep+0x80/0x88
[   79.138862] [] octeon_i2c_test_iflg+0x4c/0xbc [i2c_thunderx]
[   79.146077] [] octeon_i2c_test_ready+0x18/0x70 [i2c_thunderx]
[   79.153379] [] octeon_i2c_wait+0x154/0x1a4 [i2c_thunderx]
[   79.160334] [] octeon_i2c_xfer+0xf4/0xf60 [i2c_thunderx]

Signed-off-by: Jan Glauber 
Acked-by: Steven J. Hill 
Signed-off-by: Wolfram Sang

Revert "i2c: designware: do not disable adapter after transfer"

2016-11-25T22:23:25+00:00

This reverts commit 0317e6c0f1dc1ba86b8d9dccc010c5e77b8355fa.

Srinivas reported recently touchscreen and touchpad stopped working in
Haswell based machine in Linux 4.9-rc series with timeout errors from
i2c_designware:

[   16.508013] i2c_designware INT33C3:00: controller timed out
[   16.508302] i2c_hid i2c-MSFT0001:02: failed to change power setting.
[   17.532016] i2c_designware INT33C3:00: controller timed out
[   18.556022] i2c_designware INT33C3:00: controller timed out
[   18.556315] i2c_hid i2c-ATML1000:00: failed to retrieve report from device.

I managed to reproduce similar errors on another Haswell based machine
where touchscreen initialization fails maybe in every 1/5 - 1/2 boots.
Since root cause for these errors is not clear yet and debugging is
ongoing it's better to revert this commit as we are near to release.

Reported-by: Srinivas Pandruvada 
Signed-off-by: Jarkko Nikula 
Signed-off-by: Wolfram Sang

i2c: designware: fix rx fifo depth tracking

2016-11-24T15:18:15+00:00

When loading the TX fifo to receive bytes on the I2C bus, we incorrectly
count the number of bytes:

	rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);

	while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
		if (rx_limit - dev->rx_outstanding <= 0)
			break;
		rx_limit--;
		dev->rx_outstanding++;
	}

DW_IC_RXFLR indicates how many bytes are available to be read in the
FIFO, dev->rx_fifo_depth is the FIFO size, and dev->rx_outstanding is
the number of bytes that we've requested to be read so far, but which
have not been read.

Firstly, increasing dev->rx_outstanding and decreasing rx_limit and then
comparing them results in each byte consuming "two" bytes in this
tracking, so this is obviously wrong.

Secondly, the number of bytes that _could_ be received into the FIFO at
any time is the number of bytes we have so far requested but not yet
read from the FIFO - in other words dev->rx_outstanding.

So, in order to request enough bytes to fill the RX FIFO, we need to
request dev->rx_fifo_depth - dev->rx_outstanding bytes.

Modifying the code thusly results in us reaching the maximum number of
bytes outstanding each time we queue more "receive" operations, provided
the transfer allows that to happen.

Signed-off-by: Russell King 
Reviewed-by: Mika Westerberg 
Acked-by: Jarkko Nikula 
Signed-off-by: Wolfram Sang

i2c: designware: report short transfers

2016-11-24T15:17:34+00:00

Rather than reporting success for a short transfer due to interrupt
latency, report an error both to the caller, as well as to the kernel
log.

Signed-off-by: Russell King 
Reviewed-by: Mika Westerberg 
Acked-by: Jarkko Nikula 
Signed-off-by: Wolfram Sang

i2c: digicolor: use clk_disable_unprepare instead of clk_unprepare

2016-11-18T00:48:01+00:00

since clk_prepare_enable() is used to get i2c->clk, we should
use clk_disable_unprepare() to release it for the error path.

Signed-off-by: Wei Yongjun 
Acked-by: Baruch Siach 
Signed-off-by: Wolfram Sang

i2c: imx: defer probe if bus recovery GPIOs are not ready

2016-10-25T10:15:00+00:00

Some SoC might load the GPIO driver after the I2C driver and
using the I2C bus recovery mechanism via GPIOs. In this case
it is crucial to defer probing if the GPIO request functions
do so, otherwise the I2C driver gets loaded without recovery
mechanisms enabled.

Signed-off-by: Stefan Agner 
Acked-by: Uwe Kleine-König 
Acked-by: Li Yang 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org

i2c: designware: Avoid aborted transfers with fast reacting I2C slaves

2016-10-25T10:09:09+00:00

I2C DesignWare may abort transfer with arbitration lost if I2C slave pulls
SDA down quickly after falling edge of SCL. Reason for this is unknown but
after trial and error it was found this can be avoided by enabling non-zero
SDA RX hold time for the receiver.

By the specification SDA RX hold time extends incoming SDA low to high
transition by n * ic_clk cycles but only when SCL is high. However it
seems to help avoid above faulty arbitration lost error.

Bits 23:16 in IC_SDA_HOLD register define the SDA RX hold time for the
receiver. Be conservative and enable 1 ic_clk cycle long hold time in
case boot firmware hasn't set it up.

Reported-by: Jukka Laitinen 
Signed-off-by: Jarkko Nikula 
Tested-by: Jukka Laitinen 
Signed-off-by: Wolfram Sang

i2c: i801: Fix I2C Block Read on 8-Series/C220 and later

2016-10-25T10:00:01+00:00

Starting with the 8-Series/C220 PCH (Lynx Point), the SMBus
controller includes a SPD EEPROM protection mechanism. Once the SPD
Write Disable bit is set, only reads are allowed to slave addresses
0x50-0x57.

However the legacy implementation of I2C Block Read since the ICH5
looks like a write, and is therefore blocked by the SPD protection
mechanism. This causes the eeprom and at24 drivers to fail.

So assume that I2C Block Read is implemented as an actual read on
these chipsets. I tested it on my Q87 chipset and it seems to work
just fine.

Signed-off-by: Jean Delvare 
Tested-by: Jarkko Nikula 
[wsa: rebased to v4.9-rc2]
Signed-off-by: Wolfram Sang

i2c: xgene: Avoid dma_buffer overrun

2016-10-25T09:50:52+00:00

SMBus block command uses the first byte of buffer for the data length.
The dma_buffer should be increased by 1 to avoid the overrun issue.

Reported-by: Phil Endecott 
Signed-off-by: Hoan Tran 
Signed-off-by: Wolfram Sang 
Cc: stable@kernel.org

i2c: digicolor: Fix module autoload

2016-10-25T09:49:01+00:00

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Signed-off-by: Javier Martinez Canillas 
Acked-by: Baruch Siach 
Signed-off-by: Wolfram Sang