diff mbox series

[v2,6/6] arm64: dts: qcom: ipq8074: Fix 'max-frequency' value for sdhci node

Message ID 20220514215424.1007718-7-bhupesh.sharma@linaro.org (mailing list archive)
State Queued
Headers show
Series arm64: dts: qcom: Fix 'sdhci' nodes for 'make dtbs_check' | expand

Commit Message

Bhupesh Sharma May 14, 2022, 9:54 p.m. UTC
Since the Qualcomm sdhci-msm device-tree binding has been converted
to yaml format, 'make dtbs_check' reports issues with
'max-frequency' value for ipq8074 sdhci node:

 arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
  max-frequency:0:0: 384000000 is greater than the maximum of 200000000

Fix the same.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
---
 arch/arm64/boot/dts/qcom/ipq8074.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Bjorn Andersson June 30, 2022, 10:54 p.m. UTC | #1
On Sat 14 May 16:54 CDT 2022, Bhupesh Sharma wrote:

> Since the Qualcomm sdhci-msm device-tree binding has been converted
> to yaml format, 'make dtbs_check' reports issues with
> 'max-frequency' value for ipq8074 sdhci node:
> 
>  arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
>   max-frequency:0:0: 384000000 is greater than the maximum of 200000000
> 
> Fix the same.
> 
> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> Cc: Rob Herring <robh@kernel.org>
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> ---
>  arch/arm64/boot/dts/qcom/ipq8074.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> index ab2a1e7955b5..b2d71af9b419 100644
> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> @@ -388,7 +388,7 @@ sdhc_1: mmc@7824900 {
>  				 <&gcc GCC_SDCC1_APPS_CLK>,
>  				 <&xo>;
>  			clock-names = "iface", "core", "xo";
> -			max-frequency = <384000000>;
> +			max-frequency = <200000000>;

This might match the binding, but someone put 384000000 there for a
reason. Perhaps the binding needs to be updated instead?

Regards,
Bjorn

>  			mmc-ddr-1_8v;
>  			mmc-hs200-1_8v;
>  			mmc-hs400-1_8v;
> -- 
> 2.35.3
>
Bhupesh Sharma July 18, 2022, 8:47 a.m. UTC | #2
On 7/1/22 4:24 AM, Bjorn Andersson wrote:
> On Sat 14 May 16:54 CDT 2022, Bhupesh Sharma wrote:
>
>> Since the Qualcomm sdhci-msm device-tree binding has been converted
>> to yaml format, 'make dtbs_check' reports issues with
>> 'max-frequency' value for ipq8074 sdhci node:
>>
>>   arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
>>    max-frequency:0:0: 384000000 is greater than the maximum of 200000000
>>
>> Fix the same.
>>
>> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
>> Cc: Rob Herring <robh@kernel.org>
>> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
>> ---
>>   arch/arm64/boot/dts/qcom/ipq8074.dtsi | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> index ab2a1e7955b5..b2d71af9b419 100644
>> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>> @@ -388,7 +388,7 @@ sdhc_1: mmc@7824900 {
>>   				 <&gcc GCC_SDCC1_APPS_CLK>,
>>   				 <&xo>;
>>   			clock-names = "iface", "core", "xo";
>> -			max-frequency = <384000000>;
>> +			max-frequency = <200000000>;
> This might match the binding, but someone put 384000000 there for a
> reason. Perhaps the binding needs to be updated instead?

I was waiting for getting access to ipq8074 reference manual / documentation.
I double-checked and it seems SDCC1 on this SoC does support a max frequency
of 384 MHz which is strange as the SDCC2 supports 200 MHz as max frequency
instead.

Also the eMMC and MMC controllers on other SoCs (i.MX etx( usually support only
a max frequency of 200 MHz, so may be we need an exceptional addition to the
binding documentation here.

@Ulf - what's your view on updating the binding documentation here? I can
send a v3 accordingly.

Thanks,
Bhupesh

>>   			mmc-ddr-1_8v;
>>   			mmc-hs200-1_8v;
>>   			mmc-hs400-1_8v;
>> -- 
>> 2.35.3
>>
Ulf Hansson July 18, 2022, 12:51 p.m. UTC | #3
On Mon, 18 Jul 2022 at 10:47, Bhupesh Sharma <bhupesh.sharma@linaro.org> wrote:
>
> On 7/1/22 4:24 AM, Bjorn Andersson wrote:
> > On Sat 14 May 16:54 CDT 2022, Bhupesh Sharma wrote:
> >
> >> Since the Qualcomm sdhci-msm device-tree binding has been converted
> >> to yaml format, 'make dtbs_check' reports issues with
> >> 'max-frequency' value for ipq8074 sdhci node:
> >>
> >>   arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
> >>    max-frequency:0:0: 384000000 is greater than the maximum of 200000000
> >>
> >> Fix the same.
> >>
> >> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
> >> Cc: Rob Herring <robh@kernel.org>
> >> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
> >> ---
> >>   arch/arm64/boot/dts/qcom/ipq8074.dtsi | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> >> index ab2a1e7955b5..b2d71af9b419 100644
> >> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> >> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> >> @@ -388,7 +388,7 @@ sdhc_1: mmc@7824900 {
> >>                               <&gcc GCC_SDCC1_APPS_CLK>,
> >>                               <&xo>;
> >>                      clock-names = "iface", "core", "xo";
> >> -                    max-frequency = <384000000>;
> >> +                    max-frequency = <200000000>;
> > This might match the binding, but someone put 384000000 there for a
> > reason. Perhaps the binding needs to be updated instead?
>
> I was waiting for getting access to ipq8074 reference manual / documentation.
> I double-checked and it seems SDCC1 on this SoC does support a max frequency
> of 384 MHz which is strange as the SDCC2 supports 200 MHz as max frequency
> instead.

I guess it depends on what the property is being used for from the mmc
host driver perspective. So, to answer the question, we probably need
to look at the code in the host driver to best understand what to do
here.

>
> Also the eMMC and MMC controllers on other SoCs (i.MX etx( usually support only
> a max frequency of 200 MHz, so may be we need an exceptional addition to the
> binding documentation here.
>
> @Ulf - what's your view on updating the binding documentation here? I can
> send a v3 accordingly.

The point with the property is to let host controllers specify whether
there is an upper limit of the frequency that it can support. No
matter what, the mmc core will not use a frequency greater than stated
by the eMMC/SD/SDIO specs.

For eMMC, 200MHz is the maximum frequency.

For SD/SDIO cards, the SDR104 mode has 208MHz. So it seems like we
need an update to the binding, no matter what. :-)

I have no strong opinions around this, but perhaps just raising the
limit of the binding to cover the qcom case makes best sense.

Kind regards
Uffe
Bhupesh Sharma July 20, 2022, 7:40 a.m. UTC | #4
Hi Ulf,


On 7/18/22 6:21 PM, Ulf Hansson wrote:
> On Mon, 18 Jul 2022 at 10:47, Bhupesh Sharma <bhupesh.sharma@linaro.org> wrote:
>>
>> On 7/1/22 4:24 AM, Bjorn Andersson wrote:
>>> On Sat 14 May 16:54 CDT 2022, Bhupesh Sharma wrote:
>>>
>>>> Since the Qualcomm sdhci-msm device-tree binding has been converted
>>>> to yaml format, 'make dtbs_check' reports issues with
>>>> 'max-frequency' value for ipq8074 sdhci node:
>>>>
>>>>    arch/arm64/boot/dts/qcom/ipq8074-hk01.dtb: mmc@7824900:
>>>>     max-frequency:0:0: 384000000 is greater than the maximum of 200000000
>>>>
>>>> Fix the same.
>>>>
>>>> Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
>>>> Cc: Rob Herring <robh@kernel.org>
>>>> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
>>>> ---
>>>>    arch/arm64/boot/dts/qcom/ipq8074.dtsi | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>> index ab2a1e7955b5..b2d71af9b419 100644
>>>> --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>> +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
>>>> @@ -388,7 +388,7 @@ sdhc_1: mmc@7824900 {
>>>>                                <&gcc GCC_SDCC1_APPS_CLK>,
>>>>                                <&xo>;
>>>>                       clock-names = "iface", "core", "xo";
>>>> -                    max-frequency = <384000000>;
>>>> +                    max-frequency = <200000000>;
>>> This might match the binding, but someone put 384000000 there for a
>>> reason. Perhaps the binding needs to be updated instead?
>>
>> I was waiting for getting access to ipq8074 reference manual / documentation.
>> I double-checked and it seems SDCC1 on this SoC does support a max frequency
>> of 384 MHz which is strange as the SDCC2 supports 200 MHz as max frequency
>> instead.
> 
> I guess it depends on what the property is being used for from the mmc
> host driver perspective. So, to answer the question, we probably need
> to look at the code in the host driver to best understand what to do
> here.
> 
>>
>> Also the eMMC and MMC controllers on other SoCs (i.MX etx( usually support only
>> a max frequency of 200 MHz, so may be we need an exceptional addition to the
>> binding documentation here.
>>
>> @Ulf - what's your view on updating the binding documentation here? I can
>> send a v3 accordingly.
> 
> The point with the property is to let host controllers specify whether
> there is an upper limit of the frequency that it can support. No
> matter what, the mmc core will not use a frequency greater than stated
> by the eMMC/SD/SDIO specs.
> 
> For eMMC, 200MHz is the maximum frequency.
> 
> For SD/SDIO cards, the SDR104 mode has 208MHz. So it seems like we
> need an update to the binding, no matter what. :-)
> 
> I have no strong opinions around this, but perhaps just raising the
> limit of the binding to cover the qcom case makes best sense.

Thanks for your inputs. I will send a v3 version with the udpated
binding soon.

Regards,
Bhupesh
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
index ab2a1e7955b5..b2d71af9b419 100644
--- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
+++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
@@ -388,7 +388,7 @@  sdhc_1: mmc@7824900 {
 				 <&gcc GCC_SDCC1_APPS_CLK>,
 				 <&xo>;
 			clock-names = "iface", "core", "xo";
-			max-frequency = <384000000>;
+			max-frequency = <200000000>;
 			mmc-ddr-1_8v;
 			mmc-hs200-1_8v;
 			mmc-hs400-1_8v;