Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
3c91f25c2f
Currently bnx2x ptp worker tries to read a register with timestamp information in case of TX packet timestamping and in case it fails, the routine reschedules itself indefinitely. This was reported as a kworker always at 100% of CPU usage, which was narrowed down to be bnx2x ptp_task. By following the ioctl handler, we could narrow down the problem to an NTP tool (chrony) requesting HW timestamping from bnx2x NIC with RX filter zeroed; this isn't reproducible for example with ptp4l (from linuxptp) since this tool requests a supported RX filter. It seems NIC FW timestamp mechanism cannot work well with RX_FILTER_NONE - driver's PTP filter init routine skips a register write to the adapter if there's not a supported filter request. This patch addresses the problem of bnx2x ptp thread's everlasting reschedule by retrying the register read 10 times; between the read attempts the thread sleeps for an increasing amount of time starting in 1ms to give FW some time to perform the timestamping. If it still fails after all retries, we bail out in order to prevent an unbound resource consumption from bnx2x. The patch also adds an ethtool statistic for accounting the skipped TX timestamp packets and it reduces the priority of timestamping error messages to prevent log flooding. The code was tested using both linuxptp and chrony. Reported-and-tested-by: Przemyslaw Hausman <przemyslaw.hausman@canonical.com> Suggested-by: Sudarsana Reddy Kalluru <skalluru@marvell.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com> Acked-by: Sudarsana Reddy Kalluru <skalluru@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| init | ||
| ipc | ||
| kernel | ||
| lib | ||
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| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| COPYING | ||
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| Kbuild | ||
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| README | ||
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.