m_can offers the possibility to set an interrupt on reaching a watermark level in the receive FIFO. This can be used to implement coalescing. Unfortunately there is no hardware timeout available to trigger an interrupt if only a few messages were received within a given time. To solve this I am using a hrtimer to wake up the irq thread after x microseconds. The timer is always started if receive coalescing is enabled and new received frames were available during an interrupt. The timer is stopped if during a interrupt handling no new data was available. If the timer is started the new item interrupt is disabled and the watermark interrupt takes over. If the timer is not started again, the new item interrupt is enabled again, notifying the handler about every new item received. Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com> Link: https://lore.kernel.org/all/20240207093220.2681425-5-msp@baylibre.com Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ 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 requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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