mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Kuninori Morimoto
a8d46a7f5d
DMAC reads data from source device, and buffered it until transferable size for sink device. Because of this behavior, DMAC is including buffered data . Now, CHCR DE bit is controlling DMA transfer enable/disable. If DE bit was cleared during data transferring, or during buffering, it will flush buffered data if source device was peripheral device (The buffered data will be removed if source device was memory). Because of this behavior, driver should ensure that DE bit is actually 0 after clearing. This patch adds new rcar_dmac_chcr_de_barrier() and call it after CHCR register access. Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Tested-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com> Tested-by: Ryo Kodama <ryo.kodama.vz@renesas.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.