A built-in camera's USB device may sleep from boot

build/config/udev/60-kryptik-camera.rules

@@ -1,3 +1,8 @@
 # A granted camera taken away ends its grant at once, before another camera plugged in can take
 # its node's number: kryptikd ends it only for the granted camera's node, removed after the grant.
 ACTION=="remove", SUBSYSTEM=="video4linux", RUN+="/usr/bin/kryptikd camera gone %p %E{SEQNUM}"
+
+# The USB core keeps a device awake until its driver lets it sleep, and a camera's, uvcvideo,
+# binds here only for a grant. A built-in camera may sleep from boot; a webcam keeps the core's
+# default, as uvcvideo keeps awake a few webcams that fail when they sleep.
+ACTION=="add", SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ENV{ID_USB_INTERFACES}=="*:0e01??:*", ATTR{removable}=="fixed", TEST=="power/control", ATTR{power/control}="auto"

docs/design/laptop.md

@@ -515,7 +515,12 @@ and the power key, idle and inhibitors, suspend, and runtime directories
   schedutil (`boot.fragment`), so its clock still follows the load.
   PCIe link power and NVMe power states keep the kernel's defaults, and no
   rule turns on USB autosuspend for input devices, which too often
-  misbehave with it.
+  misbehave with it. One does for a built-in camera
+  (`60-kryptik-camera.rules`), as `uvcvideo` would when it binds, which
+  here is only for a grant; a webcam stays awake until its first grant, as
+  the USB core keeps awake a device whose driver has not let it sleep. The
+  hardware report's `camera usb` line gives the camera's port (`fixed` is
+  built in) and whether it sleeps.
 - **Brightness.** An eudev rule (`70-kryptik-backlight.rules`) gives the
   session's group, `kryptik`, write access to the backlight's level, not
   `video`, which would hand the user the GPU's device nodes past seatd.

docs/hardware.md

@@ -105,6 +105,7 @@ let the row's note name what did not work:
 | a USB-C or Thunderbolt dock: its monitor, its USB ports and its Ethernet | the monitor shows where the laptop drives USB-C itself; a Thunderbolt or USB4 dock's own USB ports and Ethernet stay dark, as 1.0 builds no Thunderbolt driver, and the row's note says which worked |
 | closed on its dock, then the dock unplugged | it sleeps within seconds, as a lid closed undocked does |
 | the state passphrase at boot, typed on the built-in keyboard | it unlocks, whether the keyboard is on PS/2 or on I2C behind Intel's LPSS or AMD's DesignWare controller; the row's note names which (`/proc/bus/input/devices`). One that types nothing there is among those status.md lists, and a plain USB keyboard is the way through |
+| the listing's `camera usb` line for the built-in camera, taken before any `k` | it reads `port fixed control auto runtime suspended`; a port that reads `unknown` keeps the camera awake, and the row's note gives the line |
 | `k` and a zone's number in the menu, then a program there that records video | a USB camera records; one the listing's `camera` line puts behind an IPU does not, as 1.0 drives none |
 | a USB camera given to a zone with `k` and its number, then pulled out | the grant ends at once, and the menu's Camera line says no zone has it; plugged back in, it waits for `k` again |
 | Firefox in `untrusted`: Alt+p, its number and `b` | a window opens; where the listing's `shstk` line says yes, this is the only test of Firefox starting with shadow stacks on, and a failure names SHSTK in what it prints |

tools/install/kryptik-hwreport.sh

@@ -437,8 +437,8 @@ nhlt() {
 # brightness.sh chooses among; each power supply, a battery's charge and kind but never its
 # serial number; the sleep states the kernel offers; and a camera's parts behind Intel's image
 # processing unit and in ACPI: its sensors, their power controller and the Visual Sensing
-# Controller between the two. A USB camera, the lid and a Bluetooth controller show under usb and
-# input.
+# Controller between the two; and whether a USB camera sleeps while idle. A USB camera's
+# interfaces, the lid and a Bluetooth controller show under usb and input.
 laptop() {
     for b in "$SYS"/class/backlight/*; do
         [ -e "$b" ] && printf 'backlight %s type %s max %s\n' "${b##*/}" "$(one "$b/type")" "$(one "$b/max_brightness")"
@@ -533,6 +533,21 @@ cameras() {
         [ "$(one "$a/status")" != 0 ] || continue
         printf 'camera acpi %s %s\n' "${a##*/}" "$w"
     done
+    # Each USB device with a video control interface (0e/01), once even when it holds an infrared
+    # camera too: whether its port is built in, and whether it sleeps while idle, which
+    # 60-kryptik-camera.rules lets a built-in one do before a grant loads its driver. A locale's
+    # collation may sort 1-11:1.0 between 1-1:1.1 and 1-1:1.2, so every device printed is kept,
+    # not only the last.
+    seen=" "
+    for i in "$SYS"/bus/usb/devices/*:*; do
+        [ "$(one "$i/bInterfaceClass")" = 0e ] && [ "$(one "$i/bInterfaceSubClass")" = 01 ] || continue
+        n="${i##*/}"; n="${n%%:*}"
+        case "$seen" in *" $n "*) continue ;; esac
+        seen="$seen$n "; d="$SYS/bus/usb/devices/$n"
+        port="$(one "$d/removable")"; pc="$(one "$d/power/control")"; rs="$(one "$d/power/runtime_status")"
+        printf 'camera usb %s %s:%s port %s control %s runtime %s\n' "$n" "$(hex "$d/idVendor")" \
+            "$(hex "$d/idProduct")" "${port:--}" "${pc:--}" "${rs:--}"
+    done
 }
 
 missing_firmware() {

tools/tests/hwreport.sh

@@ -471,6 +471,22 @@ put sys/bus/acpi/devices/INTC1009:00/status 15
 put sys/bus/acpi/devices/OVTI02C1:00/status 0
 # The OmniVision sensor behind AMD's image processor, as amdgpu's ISP looks for it.
 put sys/bus/acpi/devices/OMNI5C10:00/status 15
+# A built-in USB camera with an infrared one in it, each with its control and streaming
+# interfaces, asleep as the rule lets it; an infrared camera of its own on port 11, which a
+# locale's collation may sort among port 1's interfaces; and a webcam, left awake.
+usbdev() {   # usbdev PORT VENDOR PRODUCT REMOVABLE CONTROL STATUS IF:SUBCLASS...
+    local d="sys/devices/pci0000:00/0000:00:14.0/usb1/$1" p="$1" f; shift
+    put "$d/idVendor" "$1"; put "$d/idProduct" "$2"; put "$d/removable" "$3"
+    put "$d/power/control" "$4"; put "$d/power/runtime_status" "$5"; shift 5
+    ln -s "$W/$d" "$W/sys/bus/usb/devices/$p"
+    for f in "$@"; do
+        put "$d/$p:${f%:*}/bInterfaceClass" 0e; put "$d/$p:${f%:*}/bInterfaceSubClass" "${f#*:}"
+        ln -s "$W/$d/$p:${f%:*}" "$W/sys/bus/usb/devices/$p:${f%:*}"
+    done
+}
+usbdev 1-1 0c45 6730 fixed auto suspended 1.0:01 1.1:02 1.2:01 1.3:02
+usbdev 1-11 0c45 6731 fixed auto suspended 1.0:01 1.1:02
+usbdev 1-5 046d 085e removable on active 1.0:01
 laptop_now
 lap "each backlight with its kind and range" '^backlight intel_backlight type raw max 19200$'
 lap "the firmware's as well"                 '^backlight acpi_video0 type firmware max 100$'
@@ -490,6 +506,12 @@ lap "its sensor, by its ACPI ID"             '^camera acpi OVTI01A0:00 sensor$'
 lap "and AMD's image processor's sensor"     '^camera acpi OMNI5C10:00 sensor$'
 lap "the sensor's power controller"          '^camera acpi INT3472:01 sensor power$'
 lap "and the Visual Sensing Controller"      '^camera acpi INTC1009:00 visual sensing controller$'
+lap "a built-in USB camera, and that it sleeps" '^camera usb 1-1 0c45:6730 port fixed control auto runtime suspended$'
+lap "an infrared camera of its own"          '^camera usb 1-11 0c45:6731 port fixed control auto runtime suspended$'
+lap "a webcam, and that it is kept awake"    '^camera usb 1-5 046d:085e port removable control on runtime active$'
+[[ "$(grep -c '^camera usb 1-1 ' "$L")|$(grep -c '^camera usb 1-11 ' "$L")" == "1|1" ]] \
+    && green "each USB camera once, the one with an infrared camera in it too" \
+    || red "the USB cameras $(grep -c '^camera usb 1-1 ' "$L") and $(grep -c '^camera usb 1-11 ' "$L") times"
 nolap "not a sensor the firmware calls absent" 'OVTI02C1'
 lap "no wakeup interrupt where the kernel keeps none" '^woken by irq: -$'
 nolap "and no AMD IOMMU line without an IVRS table" '^amd iommu: '