[ Upstream commit 1d4a1adbed2582444aaf97671858b7d12915bd05 ]
In the event that the I2C bus was powered down when the I2C controller
driver loads, or some spurious pulses occur on the I2C bus, it's
possible that the controller detects a spurious I2C "start" condition.
In this situation it may continue to report the bus is busy indefinitely
and block the controller from working.
The "single-master" DT flag can be specified to disable bus busy checks
entirely, but this may not be safe to use in situations where other I2C
masters may potentially exist.
In the event that the controller reports "bus busy" for too long when
starting a transaction, we can try reinitializing the controller to see
if the busy condition clears. This allows recovering from this scenario.
Fixes: e1d5b6598cdc ("i2c: Add support for Xilinx XPS IIC Bus Interface")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Cc: <stable@vger.kernel.org> # v2.6.34+
Reviewed-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ee1691d0ae103ba7fd9439800ef454674fadad27 ]
xiic_start_xfer can fail for different reasons:
- EBUSY: bus is busy or i2c messages still in tx_msg or rx_msg
- ETIMEDOUT: timed-out trying to clear the RX fifo
- EINVAL: wrong clock settings
Both EINVAL and ETIMEDOUT will currently print a specific error
message followed by a generic one, for example:
Failed to clear rx fifo
Error xiic_start_xfer
however EBUSY will simply output the generic message:
Error xiic_start_xfer
which is not really helpful.
This commit adds a new error message when a busy condition is detected
and also removes the generic message since it does not provide any
relevant information to the user.
Signed-off-by: Marc Ferland <marc.ferland@sonatest.com>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d663d93bb47e7ab45602b227701022d8aa16040a ]
The xiic_xfer() function gets a runtime PM reference when the function is
entered. This reference is released when the function is exited. There is
currently one error path where the function exits directly, which leads to
a leak of the runtime PM reference.
Make sure that this error path also releases the runtime PM reference.
Fixes: fdacc3c7405d ("i2c: xiic: Switch from waitqueue to completion")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 294b29f15469e90893c2b72a738a962ee02a12eb ]
In case the XIIC does TX/RX transfer, make sure no other kernel thread
can start another TX transfer at the same time. This could happen since
the driver only checks tx_msg for being non-NULL and returns -EBUSY in
that case, however it is necessary to check also rx_msg for the same.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fdacc3c7405d1fc33c1f2771699a4fc24551e480 ]
There will never be threads queueing up in the xiic_xmit(), use
completion synchronization primitive to wait for the interrupt
handler thread to complete instead as it is much better fit and
there is no need to overload it for this purpose.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c119e7d00c916881913011e6f4c6ac349a41e4e2 ]
The tx_msg is set from multiple places, sometimes without locking,
which fall apart on any SMP system. Only ever access tx_msg inside
the driver mutex.
Signed-off-by: Marek Vasut <marex@denx.de>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Stable-dep-of: 1d4a1adbed25 ("i2c: xiic: Try re-initialization on bus busy timeout")
Signed-off-by: Sasha Levin <sashal@kernel.org>
