Re: [PATCH v2 0/4] amlogic: t7: give the MMC bus pipeline clock real consumers

From: Neil Armstrong

Date: Wed Sep 16 2026 - 05:56:33 EST


On 9/15/26 17:55, Lucas Tanure wrote:
On 11/09/2026 16:40, Ulf Hansson wrote:
On Sat, Sep 5, 2026 at 5:32 PM Lucas Tanure <tanure@xxxxxxxxx> wrote:

The previous series for the intermittent boot hangs on the VIM4
marked sys_ampipe_nand as critical. But as Chuan Liu from Amlogic
explained, sys_ampipe_nand clocks a pipeline stage that the
hardware design inserts in the bus path between the SD/eMMC
controllers and the NIC_MATRIX fabric to help timing closure.

So the clock has real consumers: reference it from the three MMC
controller nodes and drop CLK_IS_CRITICAL instead.

The series crosses three trees; patch 4 (clk) must only land after
patches 1-3, otherwise the DMA hangs fixed by 43e1705ecab9 come back.

Changes since v1 [3]:
  - Dropped the Fixes: tag; this series is an improvement and should not
    be picked up by stable (Jerome Brunet)
  - Moved the patch 4 dependency note below the --- so it is not kept
    for posterity (Jerome Brunet)
  - Dropped the e-mail address from the Assisted-by trailer, see
    Documentation/process/coding-assistants.rst (Jerome Brunet)
  - Fixed the space-indented error path added to meson_mmc_probe() in
    patch 2, it did not pass checkpatch
  - Dropped the CLK_PIPELINE() macro from patch 2; has_pipeline_clk is a
    capability flag, not an SD_EMMC_CLOCK register field

Thanks,
Lucas

Lucas Tanure (4):
   dt-bindings: mmc: amlogic,meson-gx-mmc: document the T7 pipeline clock
   mmc: meson-gx: enable the bus pipeline clock on T7
   arm64: dts: amlogic: t7: add the pipeline clock to the MMC controllers
   clk: meson: t7: don't mark sys_ampipe_nand as critical

  .../bindings/mmc/amlogic,meson-gx-mmc.yaml    | 29 ++++++++++++++++++-
  arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi   | 15 ++++++----
  drivers/clk/meson/t7-peripherals.c            | 10 +++----
  drivers/mmc/host/meson-gx-mmc.c               | 20 +++++++++++++
  4 files changed, 62 insertions(+), 12 deletions(-)

--
2.55.0


Patch 1 and patch2 applied for next, thanks!

Kind regards
Uffe
Hi Neil,

Any chance you could queue patch 3 for this cycle? Patch 2 is already in
next, and until the DTS lands the MMC probe fails on T7 with "missing
pipeline clock".

Done !

Thanks,
Neil


Thanks
Lucas