Re: [PATCH v11 3/6] mmc: sdhci-msm: Set ICE clk to TURBO at sdhci ICE init

From: Abhinaba Rakshit

Date: Mon Jun 22 2026 - 03:56:06 EST


On Thu, Jun 18, 2026 at 02:59:02PM +0200, Konrad Dybcio wrote:
> On 6/8/26 11:47 PM, Abhinaba Rakshit wrote:
> > MMC controller lacks a clock scaling mechanism, unlike the UFS
> > controller. By default, the MMC controller is set to TURBO mode
> > during probe, but the ICE clock remains at XO frequency,
> > leading to read/write performance degradation on eMMC.
> >
> > To address this, set the ICE clock to TURBO during sdhci_msm_ice_init
> > to align it with the controller clock. This ensures consistent
> > performance and avoids mismatches between the controller
> > and ICE clock frequencies.
> >
> > For platforms where ICE is represented as a separate device,
> > use the OPP framework to vote for TURBO mode, maintaining
> > proper voltage and power domain constraints.
> >
> > Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
> > Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> > Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> > Signed-off-by: Abhinaba Rakshit <abhinaba.rakshit@xxxxxxxxxxxxxxxx>
> > ---
> > drivers/mmc/host/sdhci-msm.c | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> > index 0882ce74e0c9bdddd98341a67b97bcef74078e0c..b655bcb5b90c0677bbe3dc6140de488038fe5ee8 100644
> > --- a/drivers/mmc/host/sdhci-msm.c
> > +++ b/drivers/mmc/host/sdhci-msm.c
> > @@ -1901,6 +1901,8 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
> > #ifdef CONFIG_MMC_CRYPTO
> >
> > static const struct blk_crypto_ll_ops sdhci_msm_crypto_ops; /* forward decl */
> > +static int sdhci_msm_ice_scale_clk(struct sdhci_msm_host *msm_host, unsigned long target_freq,
> > + bool round_ceil); /* forward decl */
>
> Can the definition simply be moved upwards?

Yes, we can do that.
I used a forward declaration because it appeared that sdhci_msm_ice_init()
was intentionally kept as the first ICE-related function in the file.
If that is not a requirement, I'm fine to move sdhci_msm_ice_scale_clk()
above and remove the forward declaration.

Abhinaba Rakshit