5e32b05c38
commit db72589c49fd260bfc99c7160c079675bc7417af upstream.
In order to optimize FIFO access, especially on m_can cores attached
to slow busses like SPI, in patch
| e39381770ec9 ("can: m_can: Disable IRQs on FIFO bus errors")
bulk read/write support has been added to the m_can_fifo_{read,write}
functions.
That change leads to the tcan driver to call
regmap_bulk_{read,write}() with a length of 0 (for CAN frames with 0
data length). regmap treats this as an error:
| tcan4x5x spi1.0 tcan4x5x0: FIFO write returned -22
This patch fixes the problem by not calling the
cdev->ops->{read,write)_fifo() in case of a 0 length read/write.
Fixes: e39381770ec9 ("can: m_can: Disable IRQs on FIFO bus errors")
Link: https://lore.kernel.org/all/20220114155751.2651888-1-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Cc: Matt Kline <matt@bitbashing.io>
Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com>
Reported-by: Michael Anochin <anochin@photo-meter.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.