From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and uses the first encoding that validates. YCbCr 4:4:4 is listed before RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the "color format" property is left at AUTO, even though RGB fits the same link. That contradicts the documented AUTO behaviour for HDMI in enum drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when the bandwidth is not available or the mode is 4:2:0-only), which the amdgpu implementation of the property also describes. It also leaves the "Broadcast RGB" property without effect on such sinks, since the quantization range it selects only applies to RGB output. Try RGB first. The mask still holds every encoding the sink supports, so a mode that cannot carry RGB falls back exactly as before. For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI sink that advertised it. Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation") Suggested-by: Adolfo Rodrigues Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- Documentation/admin-guide/aoe/aoe.rst | 150 ++++++++++++++++++++++++++ Documentation/admin-guide/aoe/autoload.sh | 17 +++ Documentation/admin-guide/aoe/examples.rst | 23 ++++ Documentation/admin-guide/aoe/index.rst | 10 ++ Documentation/admin-guide/aoe/status.sh | 30 ++++++ Documentation/admin-guide/aoe/todo.rst | 17 +++ Documentation/admin-guide/aoe/udev-install.sh | 33 ++++++ Documentation/admin-guide/aoe/udev.txt | 26 +++++ 8 files changed, 306 insertions(+) create mode 100644 Documentation/admin-guide/aoe/aoe.rst create mode 100644 Documentation/admin-guide/aoe/autoload.sh create mode 100644 Documentation/admin-guide/aoe/examples.rst create mode 100644 Documentation/admin-guide/aoe/index.rst create mode 100644 Documentation/admin-guide/aoe/status.sh create mode 100644 Documentation/admin-guide/aoe/todo.rst create mode 100644 Documentation/admin-guide/aoe/udev-install.sh create mode 100644 Documentation/admin-guide/aoe/udev.txt (limited to 'Documentation/admin-guide/aoe') diff --git a/Documentation/admin-guide/aoe/aoe.rst b/Documentation/admin-guide/aoe/aoe.rst new file mode 100644 index 000000000..a05e75136 --- /dev/null +++ b/Documentation/admin-guide/aoe/aoe.rst @@ -0,0 +1,150 @@ +Introduction +============ + +ATA over Ethernet is a network protocol that provides simple access to +block storage on the LAN. + + http://support.coraid.com/documents/AoEr11.txt + +The EtherDrive (R) HOWTO for 2.6 and 3.x kernels is found at ... + + http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO.html + +It has many tips and hints! Please see, especially, recommended +tunings for virtual memory: + + http://support.coraid.com/support/linux/EtherDrive-2.6-HOWTO-5.html#ss5.19 + +The aoetools are userland programs that are designed to work with this +driver. The aoetools are on sourceforge. + + http://aoetools.sourceforge.net/ + +The scripts in this Documentation/admin-guide/aoe directory are intended to +document the use of the driver and are not necessary if you install +the aoetools. + + +Creating Device Nodes +===================== + + Users of udev should find the block device nodes created + automatically, but to create all the necessary device nodes, use the + udev configuration rules provided in udev.txt (in this directory). + + There is a udev-install.sh script that shows how to install these + rules on your system. + + There is also an autoload script that shows how to edit + /etc/modprobe.d/aoe.conf to ensure that the aoe module is loaded when + necessary. Preloading the aoe module is preferable to autoloading, + however, because AoE discovery takes a few seconds. It can be + confusing when an AoE device is not present the first time the a + command is run but appears a second later. + +Using Device Nodes +================== + + "cat /dev/etherd/err" blocks, waiting for error diagnostic output, + like any retransmitted packets. + + "echo eth2 eth4 > /dev/etherd/interfaces" tells the aoe driver to + limit ATA over Ethernet traffic to eth2 and eth4. AoE traffic from + untrusted networks should be ignored as a matter of security. See + also the aoe_iflist driver option described below. + + "echo > /dev/etherd/discover" tells the driver to find out what AoE + devices are available. + + In the future these character devices may disappear and be replaced + by sysfs counterparts. Using the commands in aoetools insulates + users from these implementation details. + + The block devices are named like this:: + + e{shelf}.{slot} + e{shelf}.{slot}p{part} + + ... so that "e0.2" is the third blade from the left (slot 2) in the + first shelf (shelf address zero). That's the whole disk. The first + partition on that disk would be "e0.2p1". + +Using sysfs +=========== + + Each aoe block device in /sys/block has the extra attributes of + state, mac, and netif. The state attribute is "up" when the device + is ready for I/O and "down" if detected but unusable. The + "down,closewait" state shows that the device is still open and + cannot come up again until it has been closed. + + The mac attribute is the ethernet address of the remote AoE device. + The netif attribute is the network interface on the localhost + through which we are communicating with the remote AoE device. + + There is a script in this directory that formats this information in + a convenient way. Users with aoetools should use the aoe-stat + command:: + + root@makki root# sh Documentation/admin-guide/aoe/status.sh + e10.0 eth3 up + e10.1 eth3 up + e10.2 eth3 up + e10.3 eth3 up + e10.4 eth3 up + e10.5 eth3 up + e10.6 eth3 up + e10.7 eth3 up + e10.8 eth3 up + e10.9 eth3 up + e4.0 eth1 up + e4.1 eth1 up + e4.2 eth1 up + e4.3 eth1 up + e4.4 eth1 up + e4.5 eth1 up + e4.6 eth1 up + e4.7 eth1 up + e4.8 eth1 up + e4.9 eth1 up + + Use /sys/module/aoe/parameters/aoe_iflist (or better, the driver + option discussed below) instead of /dev/etherd/interfaces to limit + AoE traffic to the network interfaces in the given + whitespace-separated list. Unlike the old character device, the + sysfs entry can be read from as well as written to. + + It's helpful to trigger discovery after setting the list of allowed + interfaces. The aoetools package provides an aoe-discover script + for this purpose. You can also directly use the + /dev/etherd/discover special file described above. + +Driver Options +============== + + There is a boot option for the built-in aoe driver and a + corresponding module parameter, aoe_iflist. Without this option, + all network interfaces may be used for ATA over Ethernet. Here is a + usage example for the module parameter:: + + modprobe aoe_iflist="eth1 eth3" + + The aoe_deadsecs module parameter determines the maximum number of + seconds that the driver will wait for an AoE device to provide a + response to an AoE command. After aoe_deadsecs seconds have + elapsed, the AoE device will be marked as "down". A value of zero + is supported for testing purposes and makes the aoe driver keep + trying AoE commands forever. + + The aoe_maxout module parameter has a default of 128. This is the + maximum number of unresponded packets that will be sent to an AoE + target at one time. + + The aoe_dyndevs module parameter defaults to 1, meaning that the + driver will assign a block device minor number to a discovered AoE + target based on the order of its discovery. With dynamic minor + device numbers in use, a greater range of AoE shelf and slot + addresses can be supported. Users with udev will never have to + think about minor numbers. Using aoe_dyndevs=0 allows device nodes + to be pre-created using a static minor-number scheme with the + aoe-mkshelf script in the aoetools. diff --git a/Documentation/admin-guide/aoe/autoload.sh b/Documentation/admin-guide/aoe/autoload.sh new file mode 100644 index 000000000..815dff469 --- /dev/null +++ b/Documentation/admin-guide/aoe/autoload.sh @@ -0,0 +1,17 @@ +#!/bin/sh +# set aoe to autoload by installing the +# aliases in /etc/modprobe.d/ + +f=/etc/modprobe.d/aoe.conf + +if test ! -r $f || test ! -w $f; then + echo "cannot configure $f for module autoloading" 1>&2 + exit 1 +fi + +grep major-152 $f >/dev/null +if [ $? = 1 ]; then + echo alias block-major-152 aoe >> $f + echo alias char-major-152 aoe >> $f +fi + diff --git a/Documentation/admin-guide/aoe/examples.rst b/Documentation/admin-guide/aoe/examples.rst new file mode 100644 index 000000000..91f3198e5 --- /dev/null +++ b/Documentation/admin-guide/aoe/examples.rst @@ -0,0 +1,23 @@ +Example of udev rules +--------------------- + + .. include:: udev.txt + :literal: + +Example of udev install rules script +------------------------------------ + + .. literalinclude:: udev-install.sh + :language: shell + +Example script to get status +---------------------------- + + .. literalinclude:: status.sh + :language: shell + +Example of AoE autoload script +------------------------------ + + .. literalinclude:: autoload.sh + :language: shell diff --git a/Documentation/admin-guide/aoe/index.rst b/Documentation/admin-guide/aoe/index.rst new file mode 100644 index 000000000..564354bbc --- /dev/null +++ b/Documentation/admin-guide/aoe/index.rst @@ -0,0 +1,10 @@ +======================= +ATA over Ethernet (AoE) +======================= + +.. toctree:: + :maxdepth: 1 + + aoe + todo + examples diff --git a/Documentation/admin-guide/aoe/status.sh b/Documentation/admin-guide/aoe/status.sh new file mode 100644 index 000000000..eeec7baae --- /dev/null +++ b/Documentation/admin-guide/aoe/status.sh @@ -0,0 +1,30 @@ +#! /bin/sh +# collate and present sysfs information about AoE storage +# +# A more complete version of this script is aoe-stat, in the +# aoetools. + +set -e +format="%8s\t%8s\t%8s\n" +me=`basename $0` +sysd=${sysfs_dir:-/sys} + +# printf "$format" device mac netif state + +# Suse 9.1 Pro doesn't put /sys in /etc/mtab +#test -z "`mount | grep sysfs`" && { +test ! -d "$sysd/block" && { + echo "$me Error: sysfs is not mounted" 1>&2 + exit 1 +} + +for d in `ls -d $sysd/block/etherd* 2>/dev/null | grep -v p` end; do + # maybe ls comes up empty, so we use "end" + test $d = end && continue + + dev=`echo "$d" | sed 's/.*!//'` + printf "$format" \ + "$dev" \ + "`cat \"$d/netif\"`" \ + "`cat \"$d/state\"`" +done | sort diff --git a/Documentation/admin-guide/aoe/todo.rst b/Documentation/admin-guide/aoe/todo.rst new file mode 100644 index 000000000..dea8db5a3 --- /dev/null +++ b/Documentation/admin-guide/aoe/todo.rst @@ -0,0 +1,17 @@ +TODO +==== + +There is a potential for deadlock when allocating a struct sk_buff for +data that needs to be written out to aoe storage. If the data is +being written from a dirty page in order to free that page, and if +there are no other pages available, then deadlock may occur when a +free page is needed for the sk_buff allocation. This situation has +not been observed, but it would be nice to eliminate any potential for +deadlock under memory pressure. + +Because ATA over Ethernet is not fragmented by the kernel's IP code, +the destructor member of the struct sk_buff is available to the aoe +driver. By using a mempool for allocating all but the first few +sk_buffs, and by registering a destructor, we should be able to +efficiently allocate sk_buffs without introducing any potential for +deadlock. diff --git a/Documentation/admin-guide/aoe/udev-install.sh b/Documentation/admin-guide/aoe/udev-install.sh new file mode 100644 index 000000000..15e86f58c --- /dev/null +++ b/Documentation/admin-guide/aoe/udev-install.sh @@ -0,0 +1,33 @@ +# install the aoe-specific udev rules from udev.txt into +# the system's udev configuration +# + +me="`basename $0`" + +# find udev.conf, often /etc/udev/udev.conf +# (or environment can specify where to find udev.conf) +# +if test -z "$conf"; then + if test -r /etc/udev/udev.conf; then + conf=/etc/udev/udev.conf + else + conf="`find /etc -type f -name udev.conf 2> /dev/null`" + if test -z "$conf" || test ! -r "$conf"; then + echo "$me Error: no udev.conf found" 1>&2 + exit 1 + fi + fi +fi + +# find the directory where udev rules are stored, often +# /etc/udev/rules.d +# +rules_d="`sed -n '/^udev_rules=/{ s!udev_rules=!!; s!\"!!g; p; }' $conf`" +if test -z "$rules_d" ; then + rules_d=/etc/udev/rules.d +fi +if test ! -d "$rules_d"; then + echo "$me Error: cannot find udev rules directory" 1>&2 + exit 1 +fi +sh -xc "cp `dirname $0`/udev.txt $rules_d/60-aoe.rules" diff --git a/Documentation/admin-guide/aoe/udev.txt b/Documentation/admin-guide/aoe/udev.txt new file mode 100644 index 000000000..d55ecb411 --- /dev/null +++ b/Documentation/admin-guide/aoe/udev.txt @@ -0,0 +1,26 @@ +# These rules tell udev what device nodes to create for aoe support. +# They may be installed along the following lines. Check the section +# 8 udev manpage to see whether your udev supports SUBSYSTEM, and +# whether it uses one or two equal signs for SUBSYSTEM and KERNEL. +# +# ecashin@makki ~$ su +# Password: +# bash# find /etc -type f -name udev.conf +# /etc/udev/udev.conf +# bash# grep udev_rules= /etc/udev/udev.conf +# udev_rules="/etc/udev/rules.d/" +# bash# ls /etc/udev/rules.d/ +# 10-wacom.rules 50-udev.rules +# bash# cp /path/to/linux/Documentation/admin-guide/aoe/udev.txt \ +# /etc/udev/rules.d/60-aoe.rules +# + +# aoe char devices +SUBSYSTEM=="aoe", KERNEL=="discover", NAME="etherd/%k", GROUP="disk", MODE="0220" +SUBSYSTEM=="aoe", KERNEL=="err", NAME="etherd/%k", GROUP="disk", MODE="0440" +SUBSYSTEM=="aoe", KERNEL=="interfaces", NAME="etherd/%k", GROUP="disk", MODE="0220" +SUBSYSTEM=="aoe", KERNEL=="revalidate", NAME="etherd/%k", GROUP="disk", MODE="0220" +SUBSYSTEM=="aoe", KERNEL=="flush", NAME="etherd/%k", GROUP="disk", MODE="0220" + +# aoe block devices +KERNEL=="etherd*", GROUP="disk" -- cgit v1.3.1