mbox series

[RESEND,v3,0/3] Add ti,suppress-v1p8-ena

Message ID 20250422220512.297396-1-jm@ti.com
Headers show
Series Add ti,suppress-v1p8-ena | expand

Message

Judith Mendez April 22, 2025, 10:05 p.m. UTC 
Resend patch series to fix cc list

There are MMC boot failures seen with V1P8_SIGNAL_ENA on Kingston eMMC
and Microcenter/Patriot SD cards on Sitara K3 boards due to the HS200
initialization sequence involving V1P8_SIGNAL_ENA. Since V1P8_SIGNAL_ENA
is optional for eMMC, do not set V1P8_SIGNAL_ENA by default for eMMC.
For SD cards we shall parse DT for ti,suppress-v1p8-ena property to
determine whether to suppress V1P8_SIGNAL_ENA. Add new ti,suppress-v1p8-ena
to am62x, am62ax, and am62px SoC dtsi files since there is no internal LDO
tied to sdhci1 interface so V1P8_SIGNAL_ENA only affects timing.

This fix was previously merged in the kernel, but was reverted due
to the "heuristics for enabling the quirk"[0]. This issue is adressed
in this patch series by adding optional ti,suppress-v1p8-ena DT property
which determines whether to apply the quirk for SD.

Changes since v2:
- Include patch 3/3
- Reword cover letter
- Reword binding patch description
- Add fixes/cc tags to driver patch
- Reorder patches according to binding patch first
- Resend to fix cc list in original v3 series

Link to v2:
https://lore.kernel.org/linux-mmc/20250417182652.3521104-1-jm@ti.com/
Link to v1:
https://lore.kernel.org/linux-mmc/20250407222702.2199047-1-jm@ti.com/

[0] https://lore.kernel.org/linux-mmc/20250127-am654-mmc-regression-v2-1-9bb39fb12810@solid-run.com/

Judith Mendez (3):
  dt-bindings: mmc: sdhci-am654: Add ti,suppress-v1p8-ena
  mmc: sdhci_am654: Add sdhci_am654_start_signal_voltage_switch
  arm64: dts: ti: k3-am62*: add ti,suppress-v1p8-ena

 .../devicetree/bindings/mmc/sdhci-am654.yaml  |  5 +++
 arch/arm64/boot/dts/ti/k3-am62-main.dtsi      |  1 +
 arch/arm64/boot/dts/ti/k3-am62a-main.dtsi     |  1 +
 .../dts/ti/k3-am62p-j722s-common-main.dtsi    |  1 +
 drivers/mmc/host/sdhci_am654.c                | 32 +++++++++++++++++++
 5 files changed, 40 insertions(+)


base-commit: 1be38f81251f6d276713c259ecf4414f82f22c29

Comments

Nishanth Menon April 23, 2025, 6:08 p.m. UTC | #1 
On 17:05-20250422, Judith Mendez wrote:
> Resend patch series to fix cc list
> 
> There are MMC boot failures seen with V1P8_SIGNAL_ENA on Kingston eMMC
> and Microcenter/Patriot SD cards on Sitara K3 boards due to the HS200
> initialization sequence involving V1P8_SIGNAL_ENA. Since V1P8_SIGNAL_ENA
> is optional for eMMC, do not set V1P8_SIGNAL_ENA by default for eMMC.
> For SD cards we shall parse DT for ti,suppress-v1p8-ena property to
> determine whether to suppress V1P8_SIGNAL_ENA. Add new ti,suppress-v1p8-ena
> to am62x, am62ax, and am62px SoC dtsi files since there is no internal LDO
> tied to sdhci1 interface so V1P8_SIGNAL_ENA only affects timing.
> 
> This fix was previously merged in the kernel, but was reverted due
> to the "heuristics for enabling the quirk"[0]. This issue is adressed
> in this patch series by adding optional ti,suppress-v1p8-ena DT property
> which determines whether to apply the quirk for SD.
[...]
> 
> [0] https://lore.kernel.org/linux-mmc/20250127-am654-mmc-regression-v2-1-9bb39fb12810@solid-run.com/

Why cant we use compatible to enable the quirk instead of blindly
enabling for all IPs including ones that have onchip LDOs? That was the
reason it failed in the first place for am64x.

This is very much like a quirk that seems to go hand-in-hand with the
compatible for am62-sdhci ?

Is it worth exploring that option in the driver thread? from where I
stand, this sounds very much like an issue that AM62x IP has, and should
be handled by the driver instead of punting to dts to select where to
use and not to use the quirk.
Judith Mendez April 23, 2025, 10:27 p.m. UTC | #2 
Hi Nishanth,

On 4/23/25 1:08 PM, Nishanth Menon wrote:
> On 17:05-20250422, Judith Mendez wrote:
>> Resend patch series to fix cc list
>>
>> There are MMC boot failures seen with V1P8_SIGNAL_ENA on Kingston eMMC
>> and Microcenter/Patriot SD cards on Sitara K3 boards due to the HS200
>> initialization sequence involving V1P8_SIGNAL_ENA. Since V1P8_SIGNAL_ENA
>> is optional for eMMC, do not set V1P8_SIGNAL_ENA by default for eMMC.
>> For SD cards we shall parse DT for ti,suppress-v1p8-ena property to
>> determine whether to suppress V1P8_SIGNAL_ENA. Add new ti,suppress-v1p8-ena
>> to am62x, am62ax, and am62px SoC dtsi files since there is no internal LDO
>> tied to sdhci1 interface so V1P8_SIGNAL_ENA only affects timing.
>>
>> This fix was previously merged in the kernel, but was reverted due
>> to the "heuristics for enabling the quirk"[0]. This issue is adressed
>> in this patch series by adding optional ti,suppress-v1p8-ena DT property
>> which determines whether to apply the quirk for SD.
> [...]
>>
>> [0] https://lore.kernel.org/linux-mmc/20250127-am654-mmc-regression-v2-1-9bb39fb12810@solid-run.com/
> 
> Why cant we use compatible to enable the quirk instead of blindly
> enabling for all IPs including ones that have onchip LDOs? That was the
> reason it failed in the first place for am64x.

We made an assumption that did not work out.

> 
> This is very much like a quirk that seems to go hand-in-hand with the
> compatible for am62-sdhci ?
> 
> Is it worth exploring that option in the driver thread? from where I
> stand, this sounds very much like an issue that AM62x IP has, and should
> be handled by the driver instead of punting to dts to select where to
> use and not to use the quirk.
> 

Sure, I can test this out and respin the series. It does seem like a
more clean solution, thanks for reviewing.

~ Judith