From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- Documentation/gpu/meson.rst | 55 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) create mode 100644 Documentation/gpu/meson.rst (limited to 'Documentation/gpu/meson.rst') diff --git a/Documentation/gpu/meson.rst b/Documentation/gpu/meson.rst new file mode 100644 index 000000000..b9e2f9aa3 --- /dev/null +++ b/Documentation/gpu/meson.rst @@ -0,0 +1,55 @@ +============================================= +drm/meson AmLogic Meson Video Processing Unit +============================================= + +.. kernel-doc:: drivers/gpu/drm/meson/meson_drv.c + :doc: Video Processing Unit + +Video Processing Unit +===================== + +The Amlogic Meson Display controller is composed of several components +that are going to be documented below: + +.. code:: + + DMC|---------------VPU (Video Processing Unit)----------------|------HHI------| + | vd1 _______ _____________ _________________ | | + D |-------| |----| | | | | HDMI PLL | + D | vd2 | VIU | | Video Post | | Video Encoders |<---|-----VCLK | + R |-------| |----| Processing | | | | | + | osd2 | | | |---| Enci ----------|----|-----VDAC------| + R |-------| CSC |----| Scalers | | Encp ----------|----|----HDMI-TX----| + A | osd1 | | | Blenders | | Encl ----------|----|---------------| + M |-------|______|----|____________| |________________| | | + ___|__________________________________________________________|_______________| + +Video Input Unit +================ + +.. kernel-doc:: drivers/gpu/drm/meson/meson_viu.c + :doc: Video Input Unit + +Video Post Processing +===================== + +.. kernel-doc:: drivers/gpu/drm/meson/meson_vpp.c + :doc: Video Post Processing + +Video Encoder +============= + +.. kernel-doc:: drivers/gpu/drm/meson/meson_venc.c + :doc: Video Encoder + +Video Clocks +============ + +.. kernel-doc:: drivers/gpu/drm/meson/meson_vclk.c + :doc: Video Clocks + +HDMI Video Output +================= + +.. kernel-doc:: drivers/gpu/drm/meson/meson_dw_hdmi.c + :doc: HDMI Output -- cgit v1.3.1