linux-kernel - ath12k: REO status on PPC does not work

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <aJ7sDOoWmf4jLpjo@FUE-ALEWI-WINX>
Date: Fri, 15 Aug 2025 10:13:00 +0200
From: Alexander Wilhelm <alexander.wilhelm@...termo.com>
To: Jeff Johnson <jjohnson@...nel.org>
Cc: ath12k@...ts.infradead.org, linux-wireless@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: ath12k: REO status on PPC does not work

Hello devs,

I'm currently working on getting the 'ath12k' driver running on a big endian
PowerPC platform and have encountered the following issue.

In the function 'ath12k_dp_rx_process_reo_status', the REO status is determined
by inspecting memory that the hardware has previously written via DMA.
Specifically, during the call to 'ath12k_hal_srng_access_begin', the driver
reads the value of 'hp_addr' for the destination ring (in my case, always with
ID 21). On the big endian platform, this value is consistently 0, which prevents
the REO status from being updated.

Interestingly, DMA read/write accesses work fine for other rings, just not for
this one. What makes the REO status ring so special? I couldn’t find anything in
the initialization routine that would explain the difference.

Could anyone give me a hint on what I should be looking for?

Best regards
Alexander Wilhelm