Re: [PATCH 0/3] arm64: dts: qcom: monaco: Enable SDHCI storage support

[Monish Chunara <monish.chunara@oss.qualcomm.com>]

On Fri, Feb 27, 2026 at 10:05:32PM +0200, Dmitry Baryshkov wrote:
> On Fri, Feb 27, 2026 at 04:20:52PM +0530, Monish Chunara wrote:
> > This series enables SDHCI storage support for both SD Card and eMMC on the
> > Qualcomm Monaco EVK platform.
> > 
> > The Monaco SoC shares the SDHCI controller between SD Card and eMMC use
> > cases. Previously, the common SoC dtsi unconditionally enabled the
> > 'supports-cqe' property. This causes regression for SD cards, resulting
> > in timeouts and initialization failures during the probe sequence, as
> > the driver attempts to enable Command Queueing (CQE) logic incompatible
> > with the SD protocol.
> > 
> > To resolve this and enable full storage support, this series:
> > 
> > 1. Moves the 'supports-cqe' property out of the common SoC dtsi. It is
> >    now only enabled in the specific eMMC configuration where it is
> >    supported.
> > 2. Adds a device tree overlay to enable SD Card support (SDR/DDR modes).
> > 3. Adds a device tree overlay to enable eMMC support. This configuration
> >    also explicitly disables the UFS controller to prevent power leakage,
> >    as the VCC regulator is shared between the UFS and eMMC rails on this
> >    platform.
> > 
> > Validated on Qualcomm Monaco EVK with both SD Card and eMMC modules.
> > 
> > Monish Chunara (3):
> >   arm64: dts: qcom: monaco: Move eMMC CQE support from SoC to board DT
> >   arm64: dts: qcom: monaco-evk: Enable SDHCI for SD Card via overlay
> >   arm64: dts: qcom: monaco-evk: Add SDHCI support for eMMC via overlay
> 
> You are adding two overlays. But what does it mean? Does EVK has no uSD
> / eMMC at all, having both attachable via some kind of mezzanine? Is one
> of them attachable? Or are both cases present onboard with the correct
> one being selected by the DIP switch?
> 

The monaco EVK has both storage devices present onboard and the desired one is
selected via a DIP switch. The overlay selection logic would be based on a
fitImage metadata entry that gets populated at UEFI level by determining the
currently selected storage device (eMMC/SD) on the device.

Hence, this approach becomes robust to enable the user for using either of the
two mediums, without any additional requirement of reflashing any images.

Regards,
Monish