97c54cf2a4
It can happen that on IRQ trigger, not all conversions are done if we are enabling multiple channels. The IRQ is triggered on first EOC (end of channel), but it can happen that not all channels are done. This leads into erroneous reports to userspace (zero values or previous values). To solve this, in trigger handler, check if the mask of done channels is the same as the mask of active scan channels. If it's the same, proceed and push to buffers. Otherwise, use usleep to sleep until the conversion is done or we timeout. Normally, it should happen that in a short time fashion, all channels are ready, since the first IRQ triggered. If a hardware fault happens (for example the clock suddently dissappears), the handler will not be completed, in which case we do not report anything to userspace anymore. Also, change from using the EOC interrupts to DRDY interrupt. This helps with the fact that not 'n' interrupt statuses are enabled, each being able to trigger an interrupt, and instead only data ready interrupt can wake up the CPU. Like this, when data is ready, check in handler which and how many channels are done. While the DRDY is raised, other IRQs cannot occur. Once the channel data is being read, we ack the IRQ and finish the conversion. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
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.