| Message ID | 1478015905-31262-1-git-send-email-leogveiga@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
+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 -- 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
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 -- 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
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 -- 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
On 2016-11-02 09:40, Stefan Agner wrote: > 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... Any thoughts on this? Btw, I just realized that this used to work in 4.1 because back then the device tree properties got parsed into struct esdhc_platform_data, which does set the 1-bit quirk.. So this can be seen as a regression... -- Stefan > > -- > 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 -- 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
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)