c5c354a3a4
In the current design, udl_get_urb() may be called asynchronously during the driver freeing its URL list via udl_free_urb_list(). The problem is that the sync is determined by comparing the urbs.count and urbs.available fields, while we clear urbs.count field only once after udl_free_urb_list() finishes, i.e. during udl_free_urb_list(), the state becomes inconsistent. For fixing this inconsistency and also for hardening the locking scheme, this patch does a slight refactoring of the code around udl_get_urb() and udl_free_urb_list(). Now urbs.count is updated in the same spinlock at extracting a URB from the list in udl_free_url_list(). Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20220908095115.23396-11-tiwai@suse.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.