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Groups > linux.kernel > #1513331 > unrolled thread
| Started by | "Leonardo G. Veiga" <leogveiga@gmail.com> |
|---|---|
| First post | 2016-11-01 17:10 +0100 |
| Last post | 2016-11-02 21:10 +0100 |
| Articles | 4 — 4 participants |
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[PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. "Leonardo G. Veiga" <leogveiga@gmail.com> - 2016-11-01 17:10 +0100
Re: [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. Dong Aisheng <dongas86@gmail.com> - 2016-11-02 09:50 +0100
Re: [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. Stefan Agner <stefan@agner.ch> - 2016-11-02 17:50 +0100
RE: [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. Bough Chen <haibo.chen@nxp.com> - 2016-11-02 21:10 +0100
| From | "Leonardo G. Veiga" <leogveiga@gmail.com> |
|---|---|
| Date | 2016-11-01 17:10 +0100 |
| Subject | [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. |
| Message-ID | <syJNo-2sA-15@gated-at.bofh.it> |
From: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> The 1-bit operation mode, enabled by seeting the 'bus-width' property of the device tree 'esdhc' node to <1>, not work while using SD card. The behavior is only noticed when only the data pin 0 is connected to the hardware. A series of kernel errors are printed to the console, all of them returning the following error message followed by some explanation: mmcblk0: error -84 transferring data If four data lines are connected, it ignores the device-tree property and works in 4-bit mode of operation without errors. The hardware used for testing does not support 8-bit mode. Check the 'bus-width' property and if set to <1>, enable the SDHCI_QUIRK_FORCE_1_BIT_DATA quirk. Signed-off-by: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> --- drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index c9fbc4c3..88d7d22 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -1003,6 +1003,10 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; } + if (!of_property_read_u32(np, "bus-width", &boarddata->max_bus_width) + && boarddata->max_bus_width == 1) + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA; + /* call to generic mmc_of_parse to support additional capabilities */ ret = mmc_of_parse(host->mmc); if (ret) -- 2.7.4
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| From | Dong Aisheng <dongas86@gmail.com> |
|---|---|
| Date | 2016-11-02 09:50 +0100 |
| Message-ID | <syZp8-3X5-17@gated-at.bofh.it> |
| In reply to | #1513331 |
Hi Leonardo,
On Tue, Nov 1, 2016 at 11:58 PM, Leonardo G. Veiga <leogveiga@gmail.com> wrote:
> From: Leonardo Graboski Veiga <leonardo.veiga@toradex.com>
>
> The 1-bit operation mode, enabled by seeting the 'bus-width' property of
> the device tree 'esdhc' node to <1>, not work while using SD card.
>
> The behavior is only noticed when only the data pin 0 is connected to the
> hardware. A series of kernel errors are printed to the console, all of them
> returning the following error message followed by some explanation:
> mmcblk0: error -84 transferring data
>
> If four data lines are connected, it ignores the device-tree
> property and works in 4-bit mode of operation without errors. The hardware
> used for testing does not support 8-bit mode.
>
> Check the 'bus-width' property and if set to <1>, enable the
> SDHCI_QUIRK_FORCE_1_BIT_DATA quirk.
>
> Signed-off-by: Leonardo Graboski Veiga <leonardo.veiga@toradex.com>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index c9fbc4c3..88d7d22 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1003,6 +1003,10 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
> host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V;
> }
>
> + if (!of_property_read_u32(np, "bus-width", &boarddata->max_bus_width)
> + && boarddata->max_bus_width == 1)
> + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
> +
This looks like a common SDHCI driver issue that it assumes the default
bus-width as 4 bit if no SDHCI_QUIRK_FORCE_1_BIT_DATA specified.
if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
mmc->caps |= MMC_CAP_4_BIT_DATA;
And I'm not sure Andrian or Ulf would like to see people keep using this quirk.
IMHO we probably could totally remove it since bus-width already tells
what the driver needs.
Andrian & Ulf,
Comments?
> /* call to generic mmc_of_parse to support additional capabilities */
> ret = mmc_of_parse(host->mmc);
> if (ret)
> --
> 2.7.4
>
Regards
Dong Aisheng
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| From | Stefan Agner <stefan@agner.ch> |
|---|---|
| Date | 2016-11-02 17:50 +0100 |
| Message-ID | <sz6TE-jL-25@gated-at.bofh.it> |
| In reply to | #1513747 |
On 2016-11-02 01:42, Dong Aisheng wrote: > Hi Leonardo, > > On Tue, Nov 1, 2016 at 11:58 PM, Leonardo G. Veiga <leogveiga@gmail.com> wrote: >> From: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> >> >> The 1-bit operation mode, enabled by seeting the 'bus-width' property of >> the device tree 'esdhc' node to <1>, not work while using SD card. >> >> The behavior is only noticed when only the data pin 0 is connected to the >> hardware. A series of kernel errors are printed to the console, all of them >> returning the following error message followed by some explanation: >> mmcblk0: error -84 transferring data >> >> If four data lines are connected, it ignores the device-tree >> property and works in 4-bit mode of operation without errors. The hardware >> used for testing does not support 8-bit mode. >> >> Check the 'bus-width' property and if set to <1>, enable the >> SDHCI_QUIRK_FORCE_1_BIT_DATA quirk. >> >> Signed-off-by: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> >> --- >> drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c >> index c9fbc4c3..88d7d22 100644 >> --- a/drivers/mmc/host/sdhci-esdhc-imx.c >> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c >> @@ -1003,6 +1003,10 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev, >> host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; >> } >> >> + if (!of_property_read_u32(np, "bus-width", &boarddata->max_bus_width) >> + && boarddata->max_bus_width == 1) >> + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA; >> + > > This looks like a common SDHCI driver issue that it assumes the default > bus-width as 4 bit if no SDHCI_QUIRK_FORCE_1_BIT_DATA specified. > if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA)) > mmc->caps |= MMC_CAP_4_BIT_DATA; > > And I'm not sure Andrian or Ulf would like to see people keep using this quirk. > IMHO we probably could totally remove it since bus-width already tells > what the driver needs. Hm, I see what you are saying, the problem is that the core (sdhci_setup_host) falls back to 4-bit if SDHCI_QUIRK_FORCE_1_BIT_DATA is not set... Removing that should be fine for DT enabled SDHC drivers, since mmc_of_parse sets MMC_CAP_4_BIT_DATA. But not sure about drivers which parse dt on their own or still support platform data.... Those might rely on MMC_CAP_4_BIT_DATA being set by default... -- Stefan > > Andrian & Ulf, > Comments? > >> /* call to generic mmc_of_parse to support additional capabilities */ >> ret = mmc_of_parse(host->mmc); >> if (ret) >> -- >> 2.7.4 >> > > Regards > Dong Aisheng
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| From | Bough Chen <haibo.chen@nxp.com> |
|---|---|
| Date | 2016-11-02 21:10 +0100 |
| Message-ID | <sza1c-2sn-29@gated-at.bofh.it> |
| In reply to | #1513331 |
+Aisheng. Best Regards Haibo Chen > -----Original Message----- > From: linux-mmc-owner@vger.kernel.org [mailto:linux-mmc- > owner@vger.kernel.org] On Behalf Of Leonardo G. Veiga > Sent: Tuesday, November 01, 2016 11:58 PM > To: ulf.hansson@linaro.org > Cc: linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org; > stefan@agner.ch; raul.munoz@toradex.com; leonardo.veiga@toradex.com > Subject: [PATCH] sdhci-esdhc-imx: fix bus-width for 1-bit operation. > > From: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> > > The 1-bit operation mode, enabled by seeting the 'bus-width' property of the > device tree 'esdhc' node to <1>, not work while using SD card. > > The behavior is only noticed when only the data pin 0 is connected to the > hardware. A series of kernel errors are printed to the console, all of them > returning the following error message followed by some explanation: > mmcblk0: error -84 transferring data > > If four data lines are connected, it ignores the device-tree property and works > in 4-bit mode of operation without errors. The hardware used for testing does > not support 8-bit mode. > > Check the 'bus-width' property and if set to <1>, enable the > SDHCI_QUIRK_FORCE_1_BIT_DATA quirk. > > Signed-off-by: Leonardo Graboski Veiga <leonardo.veiga@toradex.com> > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci- > esdhc-imx.c > index c9fbc4c3..88d7d22 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -1003,6 +1003,10 @@ sdhci_esdhc_imx_probe_dt(struct platform_device > *pdev, > host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; > } > > + if (!of_property_read_u32(np, "bus-width", &boarddata- > >max_bus_width) > + && boarddata->max_bus_width == 1) > + host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA; > + > /* call to generic mmc_of_parse to support additional capabilities */ > ret = mmc_of_parse(host->mmc); > if (ret) > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the > body of a message to majordomo@vger.kernel.org More majordomo info at > http://vger.kernel.org/majordomo-info.html
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