| Message ID | 20181029221701.51376-1-rajatja@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] mmc: sdhci-pci: Try "cd" for card-detect lookup before using NULL | expand |
On 30/10/18 12:17 AM, Rajat Jain wrote: > Problem: > > The card detect IRQ does not work with modern BIOS (that want > to use _DSD to provide the card detect GPIO to the driver). > > Details: > > The mmc core provides the mmc_gpiod_request_cd() API to let host drivers > request the gpio descriptor for the "card detect" pin. > This pin is specified in the ACPI for the SDHC device: > > * Either as a resource using _CRS. This is a method used by legacy BIOS. > (The driver needs to tell which resource index). > > * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally > points to an entry in _CRS). This way, the driver can lookup using a > string. This is what modern BIOS prefer to use. > > This API finally results in a call to the following code: > > struct gpio_desc *acpi_find_gpio(..., const char *con_id,...) > { > ... > /* Lookup gpio (using "<con_id>-gpio") in the _DSD */ > ... > if (!acpi_can_fallback_to_crs(adev, con_id)) > return ERR_PTR(-ENOENT); > ... > /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */ > ... > } > > Note that this means that if the ACPI has _DSD properties, the kernel > will never use _CRS for the lookup (Because acpi_can_fallback_to_crs() > will always be false for any device hat has _DSD entries). > > The SDHCI driver is thus currently broken on a modern BIOS, even if > BIOS provides both _CRS (for index based lookup) and _DSD entries (for > string based lookup). Ironically, none of these will be used for the > lookup currently because: > > * Since the con_id is NULL, acpi_find_gpio() does not find a matching > entry in DSDT. (The _DSDT entry has the property name = "cd-gpios") > > * Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs() > returns false (because device properties have been populated from > _DSD), thus the _CRS is never used for the lookup. > > Fix: > > Try "cd" for lookup in the _DSD before falling back to using NULL so > as to try looking up in the _CRS. > > I've tested this patch successfully with both Legacy BIOS (that > provide only _CRS method) as well as modern BIOS (that provide both > _CRS and _DSD). Also the use of "cd" appears to be fairly consistent > across other users of this API (other MMC host controller drivers). > > Link: https://lkml.org/lkml/2018/9/25/1113 > Signed-off-by: Rajat Jain <rajatja@google.com> This is good enough for a fix. An ACPI GPIO mappings table can be done later. Acked-by: Adrian Hunter <adrian.hunter@intel.com> > --- > v2: Fix the commit log to take care of Andy's comments. > > drivers/mmc/host/sdhci-pci-core.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c > index 7bfd366d970d..e53333c695b3 100644 > --- a/drivers/mmc/host/sdhci-pci-core.c > +++ b/drivers/mmc/host/sdhci-pci-core.c > @@ -1762,8 +1762,13 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot( > device_init_wakeup(&pdev->dev, true); > > if (slot->cd_idx >= 0) { > - ret = mmc_gpiod_request_cd(host->mmc, NULL, slot->cd_idx, > + ret = mmc_gpiod_request_cd(host->mmc, "cd", slot->cd_idx, > slot->cd_override_level, 0, NULL); > + if (ret && ret != -EPROBE_DEFER) > + ret = mmc_gpiod_request_cd(host->mmc, NULL, > + slot->cd_idx, > + slot->cd_override_level, > + 0, NULL); > if (ret == -EPROBE_DEFER) > goto remove; > >
On 29 October 2018 at 23:17, Rajat Jain <rajatja@google.com> wrote: > Problem: > > The card detect IRQ does not work with modern BIOS (that want > to use _DSD to provide the card detect GPIO to the driver). > > Details: > > The mmc core provides the mmc_gpiod_request_cd() API to let host drivers > request the gpio descriptor for the "card detect" pin. > This pin is specified in the ACPI for the SDHC device: > > * Either as a resource using _CRS. This is a method used by legacy BIOS. > (The driver needs to tell which resource index). > > * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally > points to an entry in _CRS). This way, the driver can lookup using a > string. This is what modern BIOS prefer to use. > > This API finally results in a call to the following code: > > struct gpio_desc *acpi_find_gpio(..., const char *con_id,...) > { > ... > /* Lookup gpio (using "<con_id>-gpio") in the _DSD */ > ... > if (!acpi_can_fallback_to_crs(adev, con_id)) > return ERR_PTR(-ENOENT); > ... > /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */ > ... > } > > Note that this means that if the ACPI has _DSD properties, the kernel > will never use _CRS for the lookup (Because acpi_can_fallback_to_crs() > will always be false for any device hat has _DSD entries). > > The SDHCI driver is thus currently broken on a modern BIOS, even if > BIOS provides both _CRS (for index based lookup) and _DSD entries (for > string based lookup). Ironically, none of these will be used for the > lookup currently because: > > * Since the con_id is NULL, acpi_find_gpio() does not find a matching > entry in DSDT. (The _DSDT entry has the property name = "cd-gpios") > > * Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs() > returns false (because device properties have been populated from > _DSD), thus the _CRS is never used for the lookup. > > Fix: > > Try "cd" for lookup in the _DSD before falling back to using NULL so > as to try looking up in the _CRS. > > I've tested this patch successfully with both Legacy BIOS (that > provide only _CRS method) as well as modern BIOS (that provide both > _CRS and _DSD). Also the use of "cd" appears to be fairly consistent > across other users of this API (other MMC host controller drivers). > > Link: https://lkml.org/lkml/2018/9/25/1113 > Signed-off-by: Rajat Jain <rajatja@google.com> Applied for fixes, thanks! Should I add a stable tag to this as well? Kind regards Uffe > --- > v2: Fix the commit log to take care of Andy's comments. > > drivers/mmc/host/sdhci-pci-core.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c > index 7bfd366d970d..e53333c695b3 100644 > --- a/drivers/mmc/host/sdhci-pci-core.c > +++ b/drivers/mmc/host/sdhci-pci-core.c > @@ -1762,8 +1762,13 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot( > device_init_wakeup(&pdev->dev, true); > > if (slot->cd_idx >= 0) { > - ret = mmc_gpiod_request_cd(host->mmc, NULL, slot->cd_idx, > + ret = mmc_gpiod_request_cd(host->mmc, "cd", slot->cd_idx, > slot->cd_override_level, 0, NULL); > + if (ret && ret != -EPROBE_DEFER) > + ret = mmc_gpiod_request_cd(host->mmc, NULL, > + slot->cd_idx, > + slot->cd_override_level, > + 0, NULL); > if (ret == -EPROBE_DEFER) > goto remove; > > -- > 2.19.1.568.g152ad8e336-goog >
On Mon, Nov 12, 2018 at 1:05 PM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > On 29 October 2018 at 23:17, Rajat Jain <rajatja@google.com> wrote: > > Problem: > > > > The card detect IRQ does not work with modern BIOS (that want > > to use _DSD to provide the card detect GPIO to the driver). > > > > Details: > > > > The mmc core provides the mmc_gpiod_request_cd() API to let host drivers > > request the gpio descriptor for the "card detect" pin. > > This pin is specified in the ACPI for the SDHC device: > > > > * Either as a resource using _CRS. This is a method used by legacy BIOS. > > (The driver needs to tell which resource index). > > > > * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally > > points to an entry in _CRS). This way, the driver can lookup using a > > string. This is what modern BIOS prefer to use. > > > > This API finally results in a call to the following code: > > > > struct gpio_desc *acpi_find_gpio(..., const char *con_id,...) > > { > > ... > > /* Lookup gpio (using "<con_id>-gpio") in the _DSD */ > > ... > > if (!acpi_can_fallback_to_crs(adev, con_id)) > > return ERR_PTR(-ENOENT); > > ... > > /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */ > > ... > > } > > > > Note that this means that if the ACPI has _DSD properties, the kernel > > will never use _CRS for the lookup (Because acpi_can_fallback_to_crs() > > will always be false for any device hat has _DSD entries). > > > > The SDHCI driver is thus currently broken on a modern BIOS, even if > > BIOS provides both _CRS (for index based lookup) and _DSD entries (for > > string based lookup). Ironically, none of these will be used for the > > lookup currently because: > > > > * Since the con_id is NULL, acpi_find_gpio() does not find a matching > > entry in DSDT. (The _DSDT entry has the property name = "cd-gpios") > > > > * Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs() > > returns false (because device properties have been populated from > > _DSD), thus the _CRS is never used for the lookup. > > > > Fix: > > > > Try "cd" for lookup in the _DSD before falling back to using NULL so > > as to try looking up in the _CRS. > > > > I've tested this patch successfully with both Legacy BIOS (that > > provide only _CRS method) as well as modern BIOS (that provide both > > _CRS and _DSD). Also the use of "cd" appears to be fairly consistent > > across other users of this API (other MMC host controller drivers). > > > > Link: https://lkml.org/lkml/2018/9/25/1113 > > Signed-off-by: Rajat Jain <rajatja@google.com> > > Applied for fixes, thanks! > > Should I add a stable tag to this as well? If you go with that it might make sense to have Fixes tag against commit f10e4bf6632b5be11cea875b66ba959833a69258 Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Date: Tue May 23 20:03:19 2017 +0300 gpio: acpi: Even more tighten up ACPI GPIO lookups
On Mon, Nov 12, 2018 at 3:26 AM Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > On Mon, Nov 12, 2018 at 1:05 PM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > > > On 29 October 2018 at 23:17, Rajat Jain <rajatja@google.com> wrote: > > > Problem: > > > > > > The card detect IRQ does not work with modern BIOS (that want > > > to use _DSD to provide the card detect GPIO to the driver). > > > > > > Details: > > > > > > The mmc core provides the mmc_gpiod_request_cd() API to let host drivers > > > request the gpio descriptor for the "card detect" pin. > > > This pin is specified in the ACPI for the SDHC device: > > > > > > * Either as a resource using _CRS. This is a method used by legacy BIOS. > > > (The driver needs to tell which resource index). > > > > > > * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally > > > points to an entry in _CRS). This way, the driver can lookup using a > > > string. This is what modern BIOS prefer to use. > > > > > > This API finally results in a call to the following code: > > > > > > struct gpio_desc *acpi_find_gpio(..., const char *con_id,...) > > > { > > > ... > > > /* Lookup gpio (using "<con_id>-gpio") in the _DSD */ > > > ... > > > if (!acpi_can_fallback_to_crs(adev, con_id)) > > > return ERR_PTR(-ENOENT); > > > ... > > > /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */ > > > ... > > > } > > > > > > Note that this means that if the ACPI has _DSD properties, the kernel > > > will never use _CRS for the lookup (Because acpi_can_fallback_to_crs() > > > will always be false for any device hat has _DSD entries). > > > > > > The SDHCI driver is thus currently broken on a modern BIOS, even if > > > BIOS provides both _CRS (for index based lookup) and _DSD entries (for > > > string based lookup). Ironically, none of these will be used for the > > > lookup currently because: > > > > > > * Since the con_id is NULL, acpi_find_gpio() does not find a matching > > > entry in DSDT. (The _DSDT entry has the property name = "cd-gpios") > > > > > > * Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs() > > > returns false (because device properties have been populated from > > > _DSD), thus the _CRS is never used for the lookup. > > > > > > Fix: > > > > > > Try "cd" for lookup in the _DSD before falling back to using NULL so > > > as to try looking up in the _CRS. > > > > > > I've tested this patch successfully with both Legacy BIOS (that > > > provide only _CRS method) as well as modern BIOS (that provide both > > > _CRS and _DSD). Also the use of "cd" appears to be fairly consistent > > > across other users of this API (other MMC host controller drivers). > > > > > > Link: https://lkml.org/lkml/2018/9/25/1113 > > > Signed-off-by: Rajat Jain <rajatja@google.com> > > > > Applied for fixes, thanks! > > > > Should I add a stable tag to this as well? > > If you go with that it might make sense to have Fixes tag against > > commit f10e4bf6632b5be11cea875b66ba959833a69258 > Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Date: Tue May 23 20:03:19 2017 +0300 > > gpio: acpi: Even more tighten up ACPI GPIO lookups > I agree. Thanks, Rajat > -- > With Best Regards, > Andy Shevchenko
diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c index 7bfd366d970d..e53333c695b3 100644 --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -1762,8 +1762,13 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot( device_init_wakeup(&pdev->dev, true); if (slot->cd_idx >= 0) { - ret = mmc_gpiod_request_cd(host->mmc, NULL, slot->cd_idx, + ret = mmc_gpiod_request_cd(host->mmc, "cd", slot->cd_idx, slot->cd_override_level, 0, NULL); + if (ret && ret != -EPROBE_DEFER) + ret = mmc_gpiod_request_cd(host->mmc, NULL, + slot->cd_idx, + slot->cd_override_level, + 0, NULL); if (ret == -EPROBE_DEFER) goto remove;
Problem: The card detect IRQ does not work with modern BIOS (that want to use _DSD to provide the card detect GPIO to the driver). Details: The mmc core provides the mmc_gpiod_request_cd() API to let host drivers request the gpio descriptor for the "card detect" pin. This pin is specified in the ACPI for the SDHC device: * Either as a resource using _CRS. This is a method used by legacy BIOS. (The driver needs to tell which resource index). * Or as a named property ("cd-gpios"/"cd-gpio") in _DSD (which internally points to an entry in _CRS). This way, the driver can lookup using a string. This is what modern BIOS prefer to use. This API finally results in a call to the following code: struct gpio_desc *acpi_find_gpio(..., const char *con_id,...) { ... /* Lookup gpio (using "<con_id>-gpio") in the _DSD */ ... if (!acpi_can_fallback_to_crs(adev, con_id)) return ERR_PTR(-ENOENT); ... /* Falling back to _CRS is allowed, Lookup gpio in the _CRS */ ... } Note that this means that if the ACPI has _DSD properties, the kernel will never use _CRS for the lookup (Because acpi_can_fallback_to_crs() will always be false for any device hat has _DSD entries). The SDHCI driver is thus currently broken on a modern BIOS, even if BIOS provides both _CRS (for index based lookup) and _DSD entries (for string based lookup). Ironically, none of these will be used for the lookup currently because: * Since the con_id is NULL, acpi_find_gpio() does not find a matching entry in DSDT. (The _DSDT entry has the property name = "cd-gpios") * Because ACPI contains DSDT entries, thus acpi_can_fallback_to_crs() returns false (because device properties have been populated from _DSD), thus the _CRS is never used for the lookup. Fix: Try "cd" for lookup in the _DSD before falling back to using NULL so as to try looking up in the _CRS. I've tested this patch successfully with both Legacy BIOS (that provide only _CRS method) as well as modern BIOS (that provide both _CRS and _DSD). Also the use of "cd" appears to be fairly consistent across other users of this API (other MMC host controller drivers). Link: https://lkml.org/lkml/2018/9/25/1113 Signed-off-by: Rajat Jain <rajatja@google.com> --- v2: Fix the commit log to take care of Andy's comments. drivers/mmc/host/sdhci-pci-core.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)