Am 18.09.25 um 16:09 schrieb Andrew Lunn:
On Thu, Sep 18, 2025 at 10:46:03AM +0000, Josua Mayer wrote:
Am 12.09.25 um 00:12 schrieb Andrew Lunn:
On Thu, Sep 11, 2025 at 08:28:06PM +0200, Josua Mayer wrote:
The mvebu-comphy driver does not currently know how to pass correct lane-count to ATF while configuring the serdes lanes.
This causes the system to hard reset during reconfiguration, if a pci card is present and has established a link during bootloader.
Remove the comphy handles from the respective pci nodes to avoid runtime reconfiguration, relying solely on bootloader configuration - while avoiding the hard reset.
When bootloader has configured the lanes correctly, the pci ports are functional under Linux.
Does this require a specific bootloader? Can i use mainline grub or bareboot?
In this case it means U-Boot, i.e. before one would start grub.
I am never quite sure if in this situation I should say "firmware" instead ...
What you failed to answer is my question about 'mainline'? Do i need a specific vendor u-boot, or can i just use mainline u-boot, or mainline bareboot.
Ah.
There is no mainline u-boot for these boards (yet). I submitted v1 on u-boot ml a while back but didn't have time to rework it.
U-Boot has a different comphy driver that appears to configure the lanes correctly.
I personally like to replace the bootloader, because the one shipped with the board often has useful features disabled, or is old. If i do that, will the board work?
Conversationally if the bootloader configured the board correctly, then it also correctly configured all pci lanes considering u-boot handles link-up itself on mvebu.
I would much prefer the kernel makes no assumptions about the bootloader.
Same.
You said:
The mvebu-comphy driver does not currently know how to pass correct lane-count to ATF while configuring the serdes lanes.
Why not just teach mvebu-comphy to pass the correct line-count? That sounds like the proper fix, and that makes the kernel independent of the bootloader.
That would be a feature on the comphy driver, not a bug-fix backported to stable. The core goal was to fix bugs found in Debian 13.
The Linux comphy driver should be updated going forward. I did not due it (yet) because tracing the bitmask of atf smc call is very tedious due to layers of #define referencing each other.