915d900f6d
[ Upstream commit 855d75cf8311fee156fabb5639bb53757ca83dd4 ] There is a potential delay in notifying Linux USB drivers of downstream USB bus activity when connecting a high-speed or superSpeed device via the Microchip USB491x hub. This delay is due to the fixed bInterval value of 12 in the silicon of the Microchip USB491x hub. Microchip requested to ignore the device descriptor and decrease that value to 9 as it was too late to modify that in silicon. This patch speeds up the USB enummeration process that helps to pass Apple Carplay certifications and improve the User experience when utilizing the USB device via Microchip Multihost USB491x Hub. A new hub quirk HUB_QUIRK_REDUCE_FRAME_INTR_BINTERVAL speeds up the notification process for Microchip USB491x hub by limiting the maximum bInterval value to 9. Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20231205181829.127353-2-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.