Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1356756 > unrolled thread

Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0 Arnd Bergmann <arnd@arndb.de> - 2016-03-13 23:30 +0100
    RE: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for  T4240-R1.0-R2.0 Yangbo Lu <yangbo.lu@nxp.com> - 2016-03-14 11:10 +0100
      Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for  T4240-R1.0-R2.0 Scott Wood <scott.wood@nxp.com> - 2016-03-14 19:20 +0100
        Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for  T4240-R1.0-R2.0 Rob Herring <robh@kernel.org> - 2016-03-17 18:10 +0100
          Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0 Arnd Bergmann <arnd@arndb.de> - 2016-03-17 18:10 +0100
            Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for  T4240-R1.0-R2.0 Scott Wood <scott.wood@nxp.com> - 2016-03-18 19:30 +0100
              RE: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for  T4240-R1.0-R2.0 Yangbo Lu <yangbo.lu@nxp.com> - 2016-03-25 07:50 +0100

#1356756 — Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

On Wednesday 09 March 2016 18:08:51 Yangbo Lu wrote:
> @@ -567,10 +580,20 @@ static void esdhc_init(struct platform_device *pdev, struct sdhci_host *host)
>         struct sdhci_pltfm_host *pltfm_host;
>         struct sdhci_esdhc *esdhc;
>         u16 host_ver;
> +       u32 svr;
>  
>         pltfm_host = sdhci_priv(host);
>         esdhc = sdhci_pltfm_priv(pltfm_host);
>  
> +       fsl_guts_init();
> +       svr = fsl_guts_get_svr();
> +       if (svr) {
> +               esdhc->soc_ver = SVR_SOC_VER(svr);
> +               esdhc->soc_rev = SVR_REV(svr);
> +       } else {
> +               dev_err(&pdev->dev, "Failed to get SVR value!\n");
> +       }
> +

This makes the driver non-portable. Better identify the specific workarounds
based on the compatible string for this device, or add a boolean DT property
for the quirk.

	Arnd

[toc] | [next] | [standalone]

#1357115 — RE: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@arndb.de]
> Sent: Monday, March 14, 2016 6:26 AM
> To: linuxppc-dev@lists.ozlabs.org
> Cc: Yangbo Lu; devicetree@vger.kernel.org; linux-arm-
> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> clk@vger.kernel.org; linux-i2c@vger.kernel.org; iommu@lists.linux-
> foundation.org; netdev@vger.kernel.org; linux-mmc@vger.kernel.org;
> ulf.hansson@linaro.org; Zhao Qiang; Russell King; Bhupesh Sharma; Joerg
> Roedel; Santosh Shilimkar; Scott Wood; Rob Herring; Claudiu Manoil; Kumar
> Gala; Yang-Leo Li; Xiaobo Xie
> Subject: Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-
> R1.0-R2.0
> 
> On Wednesday 09 March 2016 18:08:51 Yangbo Lu wrote:
> > @@ -567,10 +580,20 @@ static void esdhc_init(struct platform_device
> *pdev, struct sdhci_host *host)
> >         struct sdhci_pltfm_host *pltfm_host;
> >         struct sdhci_esdhc *esdhc;
> >         u16 host_ver;
> > +       u32 svr;
> >
> >         pltfm_host = sdhci_priv(host);
> >         esdhc = sdhci_pltfm_priv(pltfm_host);
> >
> > +       fsl_guts_init();
> > +       svr = fsl_guts_get_svr();
> > +       if (svr) {
> > +               esdhc->soc_ver = SVR_SOC_VER(svr);
> > +               esdhc->soc_rev = SVR_REV(svr);
> > +       } else {
> > +               dev_err(&pdev->dev, "Failed to get SVR value!\n");
> > +       }
> > +
> 
> This makes the driver non-portable. Better identify the specific
> workarounds based on the compatible string for this device, or add a
> boolean DT property for the quirk.
> 
> 	Arnd

[Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
https://patchwork.kernel.org/patch/6834221/

We don't have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
See the link for details.

So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
Thanks.

[toc] | [prev] | [next] | [standalone]

#1357531 — Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

On 03/14/2016 02:29 AM, Yangbo Lu wrote:
>> -----Original Message-----
>> From: Arnd Bergmann [mailto:arnd@arndb.de]
>> Sent: Monday, March 14, 2016 6:26 AM
>> To: linuxppc-dev@lists.ozlabs.org
>> Cc: Yangbo Lu; devicetree@vger.kernel.org; linux-arm-
>> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
>> clk@vger.kernel.org; linux-i2c@vger.kernel.org; iommu@lists.linux-
>> foundation.org; netdev@vger.kernel.org; linux-mmc@vger.kernel.org;
>> ulf.hansson@linaro.org; Zhao Qiang; Russell King; Bhupesh Sharma; Joerg
>> Roedel; Santosh Shilimkar; Scott Wood; Rob Herring; Claudiu Manoil; Kumar
>> Gala; Yang-Leo Li; Xiaobo Xie
>> Subject: Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-
>> R1.0-R2.0
>>
>> On Wednesday 09 March 2016 18:08:51 Yangbo Lu wrote:
>>> @@ -567,10 +580,20 @@ static void esdhc_init(struct platform_device
>> *pdev, struct sdhci_host *host)
>>>         struct sdhci_pltfm_host *pltfm_host;
>>>         struct sdhci_esdhc *esdhc;
>>>         u16 host_ver;
>>> +       u32 svr;
>>>
>>>         pltfm_host = sdhci_priv(host);
>>>         esdhc = sdhci_pltfm_priv(pltfm_host);
>>>
>>> +       fsl_guts_init();
>>> +       svr = fsl_guts_get_svr();
>>> +       if (svr) {
>>> +               esdhc->soc_ver = SVR_SOC_VER(svr);
>>> +               esdhc->soc_rev = SVR_REV(svr);
>>> +       } else {
>>> +               dev_err(&pdev->dev, "Failed to get SVR value!\n");
>>> +       }
>>> +
>>
>> This makes the driver non-portable. Better identify the specific
>> workarounds based on the compatible string for this device, or add a
>> boolean DT property for the quirk.
>>
>> 	Arnd
> 
> [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
> https://patchwork.kernel.org/patch/6834221/
> 
> We don’t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
> In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
> See the link for details.
> 
> So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
> Thanks.

Also note that this driver is already only for fsl-specific hardware,
and it will still work even if fsl_guts doesn't find anything to bind to
-- it just wouldn't be able to detect errata based on SVR in that case.

-Scott

[toc] | [prev] | [next] | [standalone]

#1360053 — Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote:
> On 03/14/2016 02:29 AM, Yangbo Lu wrote:
> >> -----Original Message-----
> >> From: Arnd Bergmann [mailto:arnd@arndb.de]
> >> Sent: Monday, March 14, 2016 6:26 AM
> >> To: linuxppc-dev@lists.ozlabs.org
> >> Cc: Yangbo Lu; devicetree@vger.kernel.org; linux-arm-
> >> kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-
> >> clk@vger.kernel.org; linux-i2c@vger.kernel.org; iommu@lists.linux-
> >> foundation.org; netdev@vger.kernel.org; linux-mmc@vger.kernel.org;
> >> ulf.hansson@linaro.org; Zhao Qiang; Russell King; Bhupesh Sharma; Joerg
> >> Roedel; Santosh Shilimkar; Scott Wood; Rob Herring; Claudiu Manoil; Kumar
> >> Gala; Yang-Leo Li; Xiaobo Xie
> >> Subject: Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-
> >> R1.0-R2.0
> >>
> >> On Wednesday 09 March 2016 18:08:51 Yangbo Lu wrote:
> >>> @@ -567,10 +580,20 @@ static void esdhc_init(struct platform_device
> >> *pdev, struct sdhci_host *host)
> >>>         struct sdhci_pltfm_host *pltfm_host;
> >>>         struct sdhci_esdhc *esdhc;
> >>>         u16 host_ver;
> >>> +       u32 svr;
> >>>
> >>>         pltfm_host = sdhci_priv(host);
> >>>         esdhc = sdhci_pltfm_priv(pltfm_host);
> >>>
> >>> +       fsl_guts_init();
> >>> +       svr = fsl_guts_get_svr();
> >>> +       if (svr) {
> >>> +               esdhc->soc_ver = SVR_SOC_VER(svr);
> >>> +               esdhc->soc_rev = SVR_REV(svr);
> >>> +       } else {
> >>> +               dev_err(&pdev->dev, "Failed to get SVR value!\n");
> >>> +       }
> >>> +
> >>
> >> This makes the driver non-portable. Better identify the specific
> >> workarounds based on the compatible string for this device, or add a
> >> boolean DT property for the quirk.
> >>
> >> 	Arnd
> > 
> > [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
> > https://patchwork.kernel.org/patch/6834221/
> > 
> > We don’t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
> > In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
> > See the link for details.
> > 
> > So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
> > Thanks.
> 
> Also note that this driver is already only for fsl-specific hardware,
> and it will still work even if fsl_guts doesn't find anything to bind to
> -- it just wouldn't be able to detect errata based on SVR in that case.

IIRC, it is the same IP block as i.MX and Arnd's point is this won't 
even compile on !PPC. It is things like this that prevent sharing the 
driver. Dealing with Si revs is a common problem. We should have a 
common solution. There is soc_device for this purpose.

OTOH, the integration differences may be enough that trying to have a 
common driver with i.MX would not be worth it.

Rob

[toc] | [prev] | [next] | [standalone]

#1360055

On Thursday 17 March 2016 12:01:01 Rob Herring wrote:
> On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote:

> > >> This makes the driver non-portable. Better identify the specific
> > >> workarounds based on the compatible string for this device, or add a
> > >> boolean DT property for the quirk.
> > >>
> > >>    Arnd
> > > 
> > > [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
> > > https://patchwork.kernel.org/patch/6834221/
> > > 
> > > We don’t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
> > > In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
> > > See the link for details.
> > > 
> > > So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
> > > Thanks.
> > 
> > Also note that this driver is already only for fsl-specific hardware,
> > and it will still work even if fsl_guts doesn't find anything to bind to
> > -- it just wouldn't be able to detect errata based on SVR in that case.
> 
> IIRC, it is the same IP block as i.MX and Arnd's point is this won't 
> even compile on !PPC. It is things like this that prevent sharing the 
> driver.

I think the first four patches take care of building for ARM,
but the problem remains if you want to enable COMPILE_TEST as
we need for certain automated checking.

> Dealing with Si revs is a common problem. We should have a 
> common solution. There is soc_device for this purpose.

Exactly. The last time this came up, I think we agreed to implement a
helper using glob_match() on the soc_device strings. Unfortunately
this hasn't happened then, but I'd still prefer that over yet another
vendor-specific way of dealing with the generic issue.

	Arnd

[toc] | [prev] | [next] | [standalone]

#1360862 — Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

On 03/17/2016 12:06 PM, Arnd Bergmann wrote:
> On Thursday 17 March 2016 12:01:01 Rob Herring wrote:
>> On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote:
> 
>>>>> This makes the driver non-portable. Better identify the specific
>>>>> workarounds based on the compatible string for this device, or add a
>>>>> boolean DT property for the quirk.
>>>>>
>>>>>    Arnd
>>>>
>>>> [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
>>>> https://patchwork.kernel.org/patch/6834221/
>>>>
>>>> We don’t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
>>>> In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
>>>> See the link for details.
>>>>
>>>> So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
>>>> Thanks.
>>>
>>> Also note that this driver is already only for fsl-specific hardware,
>>> and it will still work even if fsl_guts doesn't find anything to bind to
>>> -- it just wouldn't be able to detect errata based on SVR in that case.
>>
>> IIRC, it is the same IP block as i.MX and Arnd's point is this won't 
>> even compile on !PPC. It is things like this that prevent sharing the 
>> driver.

The whole point of using the MMIO SVR instead of the PPC SPR is so that
it will work on ARM...  The guts driver should build on any platform as
long as OF is enabled, and if it doesn't find a node to bind to it will
return 0 for SVR, and the eSDHC driver will continue (after printing an
error that should be removed) without the ability to test for errata
based on SVR.

> I think the first four patches take care of building for ARM,
> but the problem remains if you want to enable COMPILE_TEST as
> we need for certain automated checking.

What specific problem is there with COMPILE_TEST?

>> Dealing with Si revs is a common problem. We should have a 
>> common solution. There is soc_device for this purpose.
> 
> Exactly. The last time this came up, I think we agreed to implement a
> helper using glob_match() on the soc_device strings. Unfortunately
> this hasn't happened then, but I'd still prefer that over yet another
> vendor-specific way of dealing with the generic issue.

soc_device would require encoding the SVR as a string and then decoding
the string, which is more complicated and error prone than having
platform-specific code test a platform-specific number.  And when would
it get registered on arm64, which doesn't have platform code?

-Scott

[toc] | [prev] | [next] | [standalone]

#1364572 — RE: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0

> -----Original Message-----
> From: Scott Wood
> Sent: Saturday, March 19, 2016 2:28 AM
> To: Arnd Bergmann; Rob Herring
> Cc: Yangbo Lu; linuxppc-dev@lists.ozlabs.org; devicetree@vger.kernel.org;
> ulf.hansson@linaro.org; Zhao Qiang; Russell King; Bhupesh Sharma;
> netdev@vger.kernel.org; Joerg Roedel; Kumar Gala; linux-
> mmc@vger.kernel.org; linux-kernel@vger.kernel.org; Yang-Leo Li;
> iommu@lists.linux-foundation.org; linux-i2c@vger.kernel.org; Claudiu
> Manoil; Santosh Shilimkar; Xiaobo Xie; linux-clk@vger.kernel.org; linux-
> arm-kernel@lists.infradead.org
> Subject: Re: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-
> R1.0-R2.0
> 
> On 03/17/2016 12:06 PM, Arnd Bergmann wrote:
> > On Thursday 17 March 2016 12:01:01 Rob Herring wrote:
> >> On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote:
> >
> >>>>> This makes the driver non-portable. Better identify the specific
> >>>>> workarounds based on the compatible string for this device, or add
> >>>>> a boolean DT property for the quirk.
> >>>>>
> >>>>>    Arnd
> >>>>
> >>>> [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS
> in v1 before.
> >>>> https://patchwork.kernel.org/patch/6834221/
> >>>>
> >>>> We don't have a separate DTS file for each revision of an SOC and if
> we did, we'd constantly have people using the wrong one.
> >>>> In addition, the device tree is stable ABI and errata are often
> discovered after device tree are deployed.
> >>>> See the link for details.
> >>>>
> >>>> So we decide to read SVR from the device-config/guts MMIO block
> other than using DTS.
> >>>> Thanks.
> >>>
> >>> Also note that this driver is already only for fsl-specific
> >>> hardware, and it will still work even if fsl_guts doesn't find
> >>> anything to bind to
> >>> -- it just wouldn't be able to detect errata based on SVR in that
> case.
> >>
> >> IIRC, it is the same IP block as i.MX and Arnd's point is this won't
> >> even compile on !PPC. It is things like this that prevent sharing the
> >> driver.
> 
> The whole point of using the MMIO SVR instead of the PPC SPR is so that
> it will work on ARM...  The guts driver should build on any platform as
> long as OF is enabled, and if it doesn't find a node to bind to it will
> return 0 for SVR, and the eSDHC driver will continue (after printing an
> error that should be removed) without the ability to test for errata
> based on SVR.
> 
> > I think the first four patches take care of building for ARM, but the
> > problem remains if you want to enable COMPILE_TEST as we need for
> > certain automated checking.
> 
> What specific problem is there with COMPILE_TEST?
> 
> >> Dealing with Si revs is a common problem. We should have a common
> >> solution. There is soc_device for this purpose.
> >
> > Exactly. The last time this came up, I think we agreed to implement a
> > helper using glob_match() on the soc_device strings. Unfortunately
> > this hasn't happened then, but I'd still prefer that over yet another
> > vendor-specific way of dealing with the generic issue.
> 
> soc_device would require encoding the SVR as a string and then decoding
> the string, which is more complicated and error prone than having
> platform-specific code test a platform-specific number.  And when would
> it get registered on arm64, which doesn't have platform code?
> 
> -Scott

[Lu Yangbo-B47093] Hi Arnd, could you answer Scott's questions?
If you don't oppose this patch, I'd like to rework a new version for merging.
Thanks.

:)

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web