Black screen after updating firmware

[carlonluca]

Is this the right place for my bug report?
Not sure if this is the right place or if I should report to firmware-nonfree. I am a bit unsure about the difference.

Describe the bug
After updating https://github.com/raspberrypi/firmware and https://github.com/RPi-Distro/firmware-nonfree, I get black screen on a couple of screen models that I typically use.

To reproduce
This issue does not happen with every screen, but I have a couple of models that show the issue.

Expected behaviour
Screen should not be black. Other devices connected to the same screen do not seem to show problems.

Actual behaviour
Screen is black, while the rest of the pi is properly working. I can even use the system via VNC, but the screen receives no signal.

System
I experienced this behavior after updating a OS I built using Yocto, but it is reproducible with the regular Raspberry OS as downloaded from the official web site.

Logs
Unfortunately, I could not find any specific error log to show. The system seems to properly work, but the screen is black. Below I attach some info about the screen.

Additional context
As said, this behavior can be reproduced using the current Raspberry Pi OS. However I experienced the issue updating an image which uses Yocto and the BSP from https://github.com/agherzan/meta-raspberrypi. I can "fix" the problem by downgrading firmware-nonfree and firmware. To be clearer, this patch to meta-raspberry fixes the issue:

diff --git a/recipes-bsp/bootfiles/rpi-bootfiles.bb b/recipes-bsp/bootfiles/rpi-bootfiles.bb
index b04f24b..e8e8f30 100644
--- a/recipes-bsp/bootfiles/rpi-bootfiles.bb
+++ b/recipes-bsp/bootfiles/rpi-bootfiles.bb
@@ -5,16 +5,7 @@ LIC_FILES_CHKSUM = "file://LICENCE.broadcom;md5=c403841ff2837657b2ed8e5bb474ac8d
 
 inherit deploy nopackages
 
-RPIFW_DATE ?= "20240319"
-SRCREV = "9f24f4bc2bdd07ffd158cfbb4bce88a2efc4c1f5"
-SHORTREV = "${@d.getVar("SRCREV", False).__str__()[:7]}"
-RPIFW_SRC_URI ?= "https://api.github.com/repos/raspberrypi/firmware/tarball/9f24f4bc2bdd07ffd158cfbb4bce88a2efc4c1f5;downloadfilename=raspberrypi-firmware-${SHORTREV}.tar.gz"
-RPIFW_S ?= "${WORKDIR}/raspberrypi-firmware-${SHORTREV}"
-
-SRC_URI = "${RPIFW_SRC_URI}"
-SRC_URI[sha256sum] = "4b436f8946b139c6a1202375ef55d4848e3bcd8c1a9cb47000e06d7ecec828f7"
-
-PV = "${RPIFW_DATE}"
+include recipes-bsp/common/raspberrypi-firmware.inc
 
 INHIBIT_DEFAULT_DEPS = "1"
 
@@ -49,4 +40,3 @@ addtask deploy before do_build after do_install
 do_deploy[dirs] += "${DEPLOYDIR}/${BOOTFILES_DIR_NAME}"
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"
-
diff --git a/recipes-kernel/linux-firmware-rpidistro/linux-firmware-rpidistro_git.bb b/recipes-kernel/linux-firmware-rpidistro/linux-firmware-rpidistro_git.bb
index 0409ba3..a4abd88 100644
--- a/recipes-kernel/linux-firmware-rpidistro/linux-firmware-rpidistro_git.bb
+++ b/recipes-kernel/linux-firmware-rpidistro/linux-firmware-rpidistro_git.bb
@@ -7,7 +7,7 @@ SECTION = "kernel"
 
 LICENSE = "GPL-2.0-only & binary-redist-Cypress-rpidistro & Synaptics-rpidistro"
 LIC_FILES_CHKSUM = "\
-    file://debian/copyright;md5=291ee5385b4cf74b10c5fb5a46a7bbc6 \
+    file://debian/copyright;md5=03475efdcf4c53c8f2d8fb4bc1fc6965 \
 "
 # Where these are no common licenses, set NO_GENERIC_LICENSE so that the
 # license files will be copied from the fetched source.
@@ -15,11 +15,11 @@ NO_GENERIC_LICENSE[binary-redist-Cypress-rpidistro] = "debian/copyright"
 NO_GENERIC_LICENSE[Synaptics-rpidistro] = "debian/copyright"
 LICENSE_FLAGS = "synaptics-killswitch"
 
-SRC_URI = "git://github.com/RPi-Distro/firmware-nonfree;branch=bookworm;protocol=https \
+SRC_URI = "git://github.com/RPi-Distro/firmware-nonfree;branch=bullseye;protocol=https \
     file://0001-Default-43455-firmware-to-standard-variant.patch \
 "
-SRCREV = "4b356e134e8333d073bd3802d767a825adec3807"
-PV = "20230625-2+rpt3"
+SRCREV = "2c3a8701193ba23d0ef85cdf0d0c9e47baf03dfc"
+PV = "20230210-5_bpo11+1"
 S = "${WORKDIR}/git"
 
 inherit allarch
@@ -70,15 +70,9 @@ FILES:${PN}-bcm43430 = " \
     ${nonarch_base_libdir}/firmware/cypress/cyfmac43430-sdio.bin \
     ${nonarch_base_libdir}/firmware/cypress/cyfmac43430-sdio.clm_blob \
 "
-FILES:${PN}-bcm43436 = " \
-    ${nonarch_base_libdir}/firmware/brcm/brcmfmac43436-* \
-    ${nonarch_base_libdir}/firmware/brcm/brcmfmac43430b0-* \
-"
+FILES:${PN}-bcm43436 = "${nonarch_base_libdir}/firmware/brcm/brcmfmac43436-*"
 FILES:${PN}-bcm43436s = "${nonarch_base_libdir}/firmware/brcm/brcmfmac43436s*"
-FILES:${PN}-bcm43439 = " \
-    ${nonarch_base_libdir}/firmware/cypress/43439A0-7.95.49.00.combined \
-    ${nonarch_base_libdir}/firmware/cypress/cyfmac43439-sdio* \
-"
+FILES:${PN}-bcm43439 = "${nonarch_base_libdir}/firmware/cypress/43439A0-7.95.49.00.combined"
 FILES:${PN}-bcm43455 = " \
     ${nonarch_base_libdir}/firmware/brcm/brcmfmac43455* \
     ${nonarch_base_libdir}/firmware/cypress/cyfmac43455-sdio* \

I can provide more info: I downloaded the screen EDID with and without my patch and I can provide the output of the modetest command.

In both systems, tvservice dumps the same EDID: edid.txt.

modetest output in the working system: modetest_ok.txt
modetest output in the "not working" system: modetest_ko.txt

As you can see, the EDID is identical, as expected, but modetest is not. In a working system (older firmware), 720p mode exists and properly works. I have no idea why the EDID does not seem to show 720p, while it exists and it works properly.

1366x768, which is the preferred mode, seems to only work for one model, but it is unstable due to other reported issues, so I cannot use it anyway (see raspberrypi/linux#3221 and raspberrypi/linux#5780). 720p is the only acceptable option.

Can someone provide info about this issue?
Thank you!

[6by9]

At a guess your old system has disable_fw_kms_setup=0 and so the firmware has inserted video=HDMI-A-1:1280x720@60 onto the kernel command line, hence 1280x720 being flagged as userdef.

More recent images set disable_fw_kms_setup=1 by default, and therefore it is purely down to the kernel parsing the EDID.