Hi On 2020-03-27 19:30, Saravana Kannan wrote: > On Fri, Mar 27, 2020 at 8:21 AM Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: >> On Fri, Mar 27, 2020 at 11:25:48AM +0100, Marek Szyprowski wrote: >>> On 2020-03-21 22:03, Saravana Kannan wrote: >>>> Set fw_devlink to "permissive" behavior by default so that device links >>>> are automatically created (with DL_FLAG_SYNC_STATE_ONLY) by scanning the >>>> firmware. >>>> >>>> This ensures suppliers get their sync_state() calls only after all their >>>> consumers have probed successfully. Without this, suppliers will get >>>> their sync_state() calls at late_initcall_sync() even if their consuer >>>> >>>> Ideally, we'd want to set fw_devlink to "on" or "rpm" by default. But >>>> that needs more testing as it's known to break some corner case >>>> drivers/platforms. >>>> >>>> Cc: Rob Herring <robh+dt@xxxxxxxxxx> >>>> Cc: Frank Rowand <frowand.list@xxxxxxxxx> >>>> Cc: devicetree@xxxxxxxxxxxxxxx >>>> Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx> >>> This patch has just landed in linux-next 20200326. Sadly it breaks >>> booting of the Raspberry Pi3b and Pi4 boards, either in 32bit or 64bit >>> mode. There is no warning nor panic message, just a silent freeze. The >>> last message shown on the earlycon is: >>> >>> [ 0.893217] Serial: 8250/16550 driver, 1 ports, IRQ sharing enabled > Marek, > > Any chance you could get me a stack trace for when it's stuck? That'd > be super helpful and I'd really appreciate it. Is it working fine on > other variants of Raspberry? I have no access to other variants of Raspberry board. The issue seems to be related to bcm2835aux_serial_driver. I've added "initcall_debug" and "ignore_loglevel" to kernel cmdline and I got the following log: [ 4.595353] calling exar_pci_driver_init+0x0/0x30 @ 1 [ 4.600597] initcall exar_pci_driver_init+0x0/0x30 returned 0 after 44 usecs [ 4.607747] calling bcm2835aux_serial_driver_init+0x0/0x28 @ 1 The with some debug printk calls I've found that the clock lookup fails with -517 (-EPROBE_DEFER) in bcm2835aux_serial_driver: https://elixir.bootlin.com/linux/v5.6/source/drivers/tty/serial/8250/8250_bcm2835aux.c#L52 Without this patch, the lookup works fine. Please let me know if you need more information. The kernel cmdline I've use is: "8250.nr_uarts=1 console=ttyS0,115200n8 earlycon=uart8250,mmio32,0x3f215040 root=/dev/mmcblk0p2 rootwait rw", kernel is compiled with bcm2835_defconfig, booted on Raspberry Pi3b+ with arch/arm/boot/dts/bcm2837-rpi-3-b.dtb Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
