Hi Jan,
On 12.01.2025 02:20, Jan Hoffmann wrote:
On 11.01.25 at 23:50, Sergey Ryazanov wrote:
It looks like VRX518 returns phys addr of data buffer in the 'data_ptr'
field of the RX descriptor and an actual data offset within the buffer
in the 'byte_off' field. In order to map the phys address back to
virtual we need the original phys address of the allocated buffer.
In the same driver applies offset to phys address before the mapping,
what leads to WARN_ON triggering in plat_mem_virt() function with
subsequent kernel panic:
WARNING: CPU: 0 PID: 0 at .../sw_plat.c:764 0xbf306cd0
[vrx518_tc@8af9f5d0+0x25000]
...
Unable to handle kernel NULL pointer dereference at virtual address
00000000
pgd = aff5701e
[00000000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Noticed in ATM mode, when chip always returns byte_off = 4.
In order to fix the issue, pass the phys address to plat_mem_virt() as
is and apply byte_off later on mapped virtual address when copying RXed
data into the skb.
VDSL still works with this patch.
Tested-by: Jan Hoffmann <j...@3e8.eu>
Thanks a lot! This patch with VDSL link worried me most of all.
Maybe the PKG_RELEASE should be increased? (Although it looks like it
also wasn't done for the last few changes to the package.)
Nice catch! Going to send V2 with one more dedicated patch updating
PKG_RELEASE.
--
Sergey
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