linux-kernel - [PATCH 0/3] mmc: meson-gx: add ddr-access-quirk support

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20190513091548.16674-1-narmstrong@baylibre.com>
Date:   Mon, 13 May 2019 11:15:45 +0200
From:   Neil Armstrong <narmstrong@...libre.com>
To:     ulf.hansson@...aro.org, khilman@...libre.com
Cc:     baylibre-upstreaming@...ups.io,
        Neil Armstrong <narmstrong@...libre.com>,
        linux-mmc@...r.kernel.org, linux-amlogic@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 0/3] mmc: meson-gx: add ddr-access-quirk support

On the Amlogic G12A SoC family, (only) the SDIO controller fails to access
the data from DDR, leading to a broken controller.

Add the amlogic,ddr-access-quirk property so signal this particular
controller has this bug and needs a quirk to work properly.

But each MMC controller has 1,5KiB of SRAM after the registers, that can
be used as bounce buffer to avoid direct DDR access from the integrated
DMAs (this SRAM may be used by the boot ROM when DDR is not yet initialized).

The quirk is to disable the chained descriptor for this controller, and
use this SRAM memory zone as buffer for the bounce buffer fallback mode.

The performance hit hasn't been evaluated, but the fix has been tested
using a WiFi AP6398S SDIO module, and the iperf3 Bandwidth measurement gave
55.2 Mbits/sec over a 63 Hours long test, with the SDIO ios set as High-Speed
at 50MHz clock. It gave around 170 Mbits/sec as SDR104 and 200MHz clock.

Neil Armstrong (3):
  dt-bindings: mmc: meson-gx: add ddr-access-quirk property
  mmc: meson-gx: add ddr-access-quirk
  arm64: dts: meson-g12a: add ddr-access-quirk property to SDIO
    controller

 .../bindings/mmc/amlogic,meson-gx.txt         |  4 ++
 arch/arm64/boot/dts/amlogic/meson-g12a.dtsi   |  1 +
 drivers/mmc/host/meson-gx-mmc.c               | 65 +++++++++++++++----
 3 files changed, 57 insertions(+), 13 deletions(-)

-- 
2.21.0