Hi all, I think I have found the issue, it is not ZONE_DMA, see below. > Am 14.12.2019 um 17:54 schrieb Stefan Wahren <wahrenst@xxxxxxx>: > > Hi Nikolaus, > > [add Nicolas as the new BCM2835 maintainer] > > Am 14.12.19 um 11:54 schrieb H. Nikolaus Schaller: >> Hi Stefan, >> >>> Am 15.10.2019 um 19:15 schrieb Stefan Wahren <wahrenst@xxxxxxx>: >>> >>> Hi Florian, >>> >>> The following changes since commit 54ecb8f7028c5eb3d740bb82b0f1d90f2df63c5c: >>> >>> Linux 5.4-rc1 (2019-09-30 10:35:40 -0700) >>> >>> are available in the git repository at: >>> >>> git://github.com/anholt/linux tags/bcm2835-soc-next-2019-10-15 >>> >>> for you to fetch changes up to 781fa0a954240c8487683ddf837fb2c4ede8e7ca: >>> >>> ARM: bcm: Add support for BCM2711 SoC (2019-10-10 19:21:03 +0200) >> this patch has finally arrived in v5.5-rc1 but it seems to break >> multiplatform build. >> >> We run a distribution kernel that supports OMAP3/4/5, i.MX6 and RasPi 3B+ >> but since rebasing to v5.5-rc1 the kernel hangs after "Starting Kernel ...". >> On all ARM devices (incl. RasPi 3B+). > > i wasn't able to reproduce this issue with the RPi 3B+ so far and i > don't have any OMAP hardware: > > Linux 5.3 (bcm2835_defconfig) + FW 2019-02-12 => okay > Linux 5.3 (bcm2835_defconfig + ZONE_DMA) + FW 2019-02-12 => okay > Linux 5.5-rc1 (bcm2835_defconfig) + FW 2019-02-12 => okay > Linux 5.5-rc1 (multi_v7_defconfig) + FW 2019-02-12 => okay > > So please provide more information about your RPi 3B+ setup: > > - VC firmware version > - additional bootloader (U-Boot) > - boot source (SD card, USB, network) > - kernel config > > Did you tested the mainline kernel or the letux kernel? On the OMAP I did test the mainline kernel with omap2plus_defconfig. RasPi 3B+ experiment was with Letux kernel and config. But I was lucky to find the issue by code inspection: bcm2711_compat[] is missing a NULL sentinel. Therefore, enabling CONFIG_ARCH_BCM2835 is sufficient to trigger the problem unless you may have been lucky getting something starting with a NULL packed after it on your bcm2835_defconfig or multi_v7_defconfig build. Patch submitted. BR, Nikolaus
