From: Kevin Hilman <khilman@baylibre.com>
To: Neil Armstrong <narmstrong@baylibre.com>,
dri-devel@lists.freedesktop.org
Cc: linux-amlogic@lists.infradead.org,
linux-arm-kernel@lists.infradead.org,
Neil Armstrong <narmstrong@baylibre.com>
Subject: Re: [PATCH v2 0/3] drm/meson: implement RDMA for AFBC reset on vsync
Date: Mon, 09 Dec 2019 14:03:42 -0800 [thread overview]
Message-ID: <7hpngxrwap.fsf@baylibre.com> (raw)
In-Reply-To: <20191017094826.21552-1-narmstrong@baylibre.com>
Neil Armstrong <narmstrong@baylibre.com> writes:
> The VPU embeds a "Register DMA" that can write a sequence of registers
> on the VPU AHB bus, either manually or triggered by an internal IRQ
> event like VSYNC or a line input counter.
>
> The initial implementation handles a single channel (over 8), triggered
> by the VSYNC irq and does not handle the RDMA irq.
>
> The RDMA will be usefull to reset and program the AFBC decoder unit
> on each vsync without involving the interrupt handler that can
> be masked for a long period of time, producing display glitches.
>
> For this we use the meson_rdma_writel_sync() which adds the register
> write tuple (VPU register offset and register value) to the RDMA buffer
> and write the value to the HW.
>
> When enabled, the RDMA is enabled to rewritte the same sequence at the
> next VSYNC event, until a new buffer is committed to the OSD plane.
>
> The the Amlogic G12A is switched to RDMA, the Amlogic GXM Decoder
> doesn't need a reset/reprogram at each vsync.
>
> Changes since v1 at [1]:
> - Fixed a regression when AFBC was not used, adding a reset() call for the afbc module
> - Added a define for the RDMA descriptor size
> - Fixed overflow detection
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
prev parent reply other threads:[~2019-12-09 22:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 9:48 [PATCH v2 0/3] drm/meson: implement RDMA for AFBC reset on vsync Neil Armstrong
2019-10-17 9:48 ` [PATCH v2 1/3] drm/meson: add RDMA register bits defines Neil Armstrong
2019-10-17 9:48 ` [PATCH v2 2/3] drm/meson: add RDMA module driver Neil Armstrong
2019-10-17 9:48 ` [PATCH v2 3/3] drm/meson: use RDMA to reconfigure AFBC on vsync Neil Armstrong
2019-12-09 22:03 ` Kevin Hilman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7hpngxrwap.fsf@baylibre.com \
--to=khilman@baylibre.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-amlogic@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=narmstrong@baylibre.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).