| Message ID | 1372177330-28013-6-git-send-email-mika.westerberg@linux.intel.com |
|---|---|
| State | Superseded |
| Headers | show |
On Tue, Jun 25, 2013 at 7:22 PM, Mika Westerberg <mika.westerberg@linux.intel.com> wrote: > The acpiphp driver finds out whether the device is hotpluggable by checking > whether it has _RMV method behind it (and if it returns 1). However, at > least Acer Aspire S5 with Thunderbolt host router has this method placed > behind device called EPUP (endpoint upstream port?) and not directly behind > the root port as can be seen from the ASL code below: [] > +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl, > + void *context, void **return_not_used) > +{ > + unsigned long long *removable = context; > + unsigned long long value; > + acpi_status status; > + > + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value); > + if (ACPI_SUCCESS(status) && value) { So, there is a chance the caller gets back uninitialized *context. Let's assume that is by design. > + *removable = value; > + return AE_CTRL_TERMINATE; > + } > + return AE_OK; > +} > +static bool pcihp_is_removable(acpi_handle handle, size_t depth) > +{ > + unsigned long long removable = 0; > + acpi_status status; > + > + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL); > + if ((status == AE_CTRL_TERMINATE) && removable) Here you already have removable not equal zero. Internal braces could be removed, but it's up top you. > + return true; > + > + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, depth, pcihp_evaluate_rmv, > + NULL, &removable, NULL); > + return !!removable; > +} -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 25, 2013 at 09:15:47PM +0300, Andy Shevchenko wrote: > On Tue, Jun 25, 2013 at 7:22 PM, Mika Westerberg > <mika.westerberg@linux.intel.com> wrote: > > > The acpiphp driver finds out whether the device is hotpluggable by checking > > whether it has _RMV method behind it (and if it returns 1). However, at > > least Acer Aspire S5 with Thunderbolt host router has this method placed > > behind device called EPUP (endpoint upstream port?) and not directly behind > > the root port as can be seen from the ASL code below: > > [] > > > > +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl, > > + void *context, void **return_not_used) > > +{ > > + unsigned long long *removable = context; > > + unsigned long long value; > > + acpi_status status; > > + > > + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value); > > + if (ACPI_SUCCESS(status) && value) { > > So, there is a chance the caller gets back uninitialized *context. > Let's assume that is by design. > > > + *removable = value; > > + return AE_CTRL_TERMINATE; > > + } > > + return AE_OK; > > +} > > > > +static bool pcihp_is_removable(acpi_handle handle, size_t depth) > > +{ > > + unsigned long long removable = 0; > > + acpi_status status; > > + > > + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL); > > + if ((status == AE_CTRL_TERMINATE) && removable) > > Here you already have removable not equal zero. Hmm, removable is initialized to zero just few lines above... Did I miss something obvious? > Internal braces could be removed, but it's up top you. I'll remove them in the next revision. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 25, 2013 at 9:31 PM, Mika Westerberg <mika.westerberg@linux.intel.com> wrote: > On Tue, Jun 25, 2013 at 09:15:47PM +0300, Andy Shevchenko wrote: >> On Tue, Jun 25, 2013 at 7:22 PM, Mika Westerberg >> <mika.westerberg@linux.intel.com> wrote: [] >> > +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl, >> > + void *context, void **return_not_used) >> > +{ >> > + unsigned long long *removable = context; >> > + unsigned long long value; >> > + acpi_status status; >> > + >> > + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value); >> > + if (ACPI_SUCCESS(status) && value) { >> >> So, there is a chance the caller gets back uninitialized *context. >> Let's assume that is by design. >> >> > + *removable = value; >> > + return AE_CTRL_TERMINATE; >> > + } >> > + return AE_OK; >> > +} >> >> >> > +static bool pcihp_is_removable(acpi_handle handle, size_t depth) >> > +{ >> > + unsigned long long removable = 0; >> > + acpi_status status; >> > + >> > + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL); >> > + if ((status == AE_CTRL_TERMINATE) && removable) >> >> Here you already have removable not equal zero. > > Hmm, removable is initialized to zero just few lines above... Did I miss > something obvious? Yes, that's correct, however, you already did this check when you call evaluate_rmv. Thus, second check '&& removable' is not needed. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 25, 2013 at 09:31:52PM +0300, Andy Shevchenko wrote: > On Tue, Jun 25, 2013 at 9:31 PM, Mika Westerberg > <mika.westerberg@linux.intel.com> wrote: > > On Tue, Jun 25, 2013 at 09:15:47PM +0300, Andy Shevchenko wrote: > >> On Tue, Jun 25, 2013 at 7:22 PM, Mika Westerberg > >> <mika.westerberg@linux.intel.com> wrote: > > [] > > >> > +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl, > >> > + void *context, void **return_not_used) > >> > +{ > >> > + unsigned long long *removable = context; > >> > + unsigned long long value; > >> > + acpi_status status; > >> > + > >> > + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value); > >> > + if (ACPI_SUCCESS(status) && value) { > >> > >> So, there is a chance the caller gets back uninitialized *context. > >> Let's assume that is by design. > >> > >> > + *removable = value; > >> > + return AE_CTRL_TERMINATE; > >> > + } > >> > + return AE_OK; > >> > +} > >> > >> > >> > +static bool pcihp_is_removable(acpi_handle handle, size_t depth) > >> > +{ > >> > + unsigned long long removable = 0; > >> > + acpi_status status; > >> > + > >> > + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL); > >> > + if ((status == AE_CTRL_TERMINATE) && removable) > >> > >> Here you already have removable not equal zero. > > > > Hmm, removable is initialized to zero just few lines above... Did I miss > > something obvious? > > Yes, that's correct, however, you already did this check when you call > evaluate_rmv. Thus, second check '&& removable' is not needed. Ah, right. Got it now :-) I think it is better to remove the first value check from the pcihp_evaluate_rmv() and keep the check here. I'll fix that in the next revision as well. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Jun 25, 2013 at 9:51 PM, Mika Westerberg <mika.westerberg@linux.intel.com> wrote: > On Tue, Jun 25, 2013 at 09:31:52PM +0300, Andy Shevchenko wrote: > I think it is better to remove the first value check from the > pcihp_evaluate_rmv() and keep the check here. > > I'll fix that in the next revision as well. In that case you may remove the removable assignment as well. -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Mika Westerberg wrote: > The acpiphp driver finds out whether the device is hotpluggable by checking > whether it has _RMV method behind it (and if it returns 1). However, at > least Acer Aspire S5 with Thunderbolt host router has this method placed > behind device called EPUP (endpoint upstream port?) and not directly behind > the root port as can be seen from the ASL code below: > > Device (RP05) > { > ... > Device (HRUP) > { > Name (_ADR, Zero) > Name (_PRW, Package (0x02) > { > 0x09, > 0x04 > }) > Device (HRDN) > { > Name (_ADR, 0x00040000) > Name (_PRW, Package (0x02) > { > 0x09, > 0x04 > }) > Device (EPUP) > { > Name (_ADR, Zero) > Method (_RMV, 0, NotSerialized) > { > Return (One) > } > } > } > } > > If we want to support such machines we must look for the _RMV method a bit > deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check > few more devices down from the root port. We found that this approach is broken. We've got false positive: host bridge itself was detected as hotplugable slot %) I think it's not acceptable. Mika has tried few more approaches, but we haven't found anything better then hardcoded path like in original workaround patch[1]. It's not generic at all, but safe from false positives. Any thoughts? [1] http://article.gmane.org/gmane.linux.kernel.pci/19102
On Tue, Jul 2, 2013 at 4:44 AM, Kirill A. Shutemov <kirill.shutemov@linux.intel.com> wrote: > Mika Westerberg wrote: >> The acpiphp driver finds out whether the device is hotpluggable by checking >> whether it has _RMV method behind it (and if it returns 1). However, at >> least Acer Aspire S5 with Thunderbolt host router has this method placed >> behind device called EPUP (endpoint upstream port?) and not directly behind >> the root port as can be seen from the ASL code below: >> >> Device (RP05) >> { >> ... >> Device (HRUP) >> { >> Name (_ADR, Zero) >> Name (_PRW, Package (0x02) >> { >> 0x09, >> 0x04 >> }) >> Device (HRDN) >> { >> Name (_ADR, 0x00040000) >> Name (_PRW, Package (0x02) >> { >> 0x09, >> 0x04 >> }) >> Device (EPUP) >> { >> Name (_ADR, Zero) >> Method (_RMV, 0, NotSerialized) >> { >> Return (One) >> } >> } >> } >> } >> >> If we want to support such machines we must look for the _RMV method a bit >> deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check >> few more devices down from the root port. > > We found that this approach is broken. We've got false positive: host > bridge itself was detected as hotplugable slot %) I think it's not > acceptable. > > Mika has tried few more approaches, but we haven't found anything better > then hardcoded path like in original workaround patch[1]. It's not generic > at all, but safe from false positives. > > Any thoughts? > > [1] http://article.gmane.org/gmane.linux.kernel.pci/19102 The changelog of this patch ([1]) says "Correct ACPI PCI hotplug implementation should have _RMV method in a PCI slot (device under pci bridge). In Acer Aspire S5 case we have it deeper in hierarchy ..." This is exactly what I mean about acpiphp being brittle because of the assumptions it makes about the ACPI namespace. Is there actually something in the spec that requires the _RMV method to be where pcihp_is_ejectable() expects it? I'm not 100% dead-set against merging the workaround with hard-coded path, but I still don't think it's a good idea. It "fixes" it for one particular machine, but there will likely be other machines that require similar fixes in the future. It makes it harder for somebody to clean up the design later, because that person won't have an Aspire S5 to test. It makes it less likely that somebody *will* clean it up later, because "everything is already working." That's why my preference (given infinite resources) would be to rework acpiphp now, while people are interested and can test it. I'm sure this would be a major redesign of acpiphp and its interaction with pciehp, but I think it's something we're going to have to do at some point. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Bjorn Helgaas wrote: > On Tue, Jul 2, 2013 at 4:44 AM, Kirill A. Shutemov > <kirill.shutemov@linux.intel.com> wrote: > > Mika Westerberg wrote: > >> The acpiphp driver finds out whether the device is hotpluggable by checking > >> whether it has _RMV method behind it (and if it returns 1). However, at > >> least Acer Aspire S5 with Thunderbolt host router has this method placed > >> behind device called EPUP (endpoint upstream port?) and not directly behind > >> the root port as can be seen from the ASL code below: > >> > >> Device (RP05) > >> { > >> ... > >> Device (HRUP) > >> { > >> Name (_ADR, Zero) > >> Name (_PRW, Package (0x02) > >> { > >> 0x09, > >> 0x04 > >> }) > >> Device (HRDN) > >> { > >> Name (_ADR, 0x00040000) > >> Name (_PRW, Package (0x02) > >> { > >> 0x09, > >> 0x04 > >> }) > >> Device (EPUP) > >> { > >> Name (_ADR, Zero) > >> Method (_RMV, 0, NotSerialized) > >> { > >> Return (One) > >> } > >> } > >> } > >> } > >> > >> If we want to support such machines we must look for the _RMV method a bit > >> deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check > >> few more devices down from the root port. > > > > We found that this approach is broken. We've got false positive: host > > bridge itself was detected as hotplugable slot %) I think it's not > > acceptable. > > > > Mika has tried few more approaches, but we haven't found anything better > > then hardcoded path like in original workaround patch[1]. It's not generic > > at all, but safe from false positives. > > > > Any thoughts? > > > > [1] http://article.gmane.org/gmane.linux.kernel.pci/19102 > > The changelog of this patch ([1]) says "Correct ACPI PCI hotplug > implementation should have _RMV method in a PCI slot (device under pci > bridge). In Acer Aspire S5 case we have it deeper in hierarchy ..." > > This is exactly what I mean about acpiphp being brittle because of the > assumptions it makes about the ACPI namespace. Is there actually > something in the spec that requires the _RMV method to be where > pcihp_is_ejectable() expects it? Spec says that _RMV indicates the device which can be removed. Rest, I believe, are assumptions: if the device is removable, then parent must be a hotpluggable slot. It looks reasonable, but doesn't work in this case. And it's not obvious how we can generalize the assumption to cover the case. > I'm not 100% dead-set against merging the workaround with hard-coded > path, but I still don't think it's a good idea. It "fixes" it for one > particular machine, but there will likely be other machines that > require similar fixes in the future. It makes it harder for somebody > to clean up the design later, because that person won't have an Aspire > S5 to test. It makes it less likely that somebody *will* clean it up > later, because "everything is already working." > > That's why my preference (given infinite resources) would be to rework > acpiphp now, while people are interested and can test it. I'm sure > this would be a major redesign of acpiphp and its interaction with > pciehp, but I think it's something we're going to have to do at some > point. Basically, we run out of ideas. Any input is welcome! :) For now we can post new version of patchset without the workaround and come back later with workaround (or proper solution if we'll find any). Does it work for you? Or you prefer everything in one patchset?
On Tuesday, July 02, 2013 11:09:19 AM Bjorn Helgaas wrote: > On Tue, Jul 2, 2013 at 4:44 AM, Kirill A. Shutemov > <kirill.shutemov@linux.intel.com> wrote: > > Mika Westerberg wrote: > >> The acpiphp driver finds out whether the device is hotpluggable by checking > >> whether it has _RMV method behind it (and if it returns 1). However, at > >> least Acer Aspire S5 with Thunderbolt host router has this method placed > >> behind device called EPUP (endpoint upstream port?) and not directly behind > >> the root port as can be seen from the ASL code below: > >> > >> Device (RP05) > >> { > >> ... > >> Device (HRUP) > >> { > >> Name (_ADR, Zero) > >> Name (_PRW, Package (0x02) > >> { > >> 0x09, > >> 0x04 > >> }) > >> Device (HRDN) > >> { > >> Name (_ADR, 0x00040000) > >> Name (_PRW, Package (0x02) > >> { > >> 0x09, > >> 0x04 > >> }) > >> Device (EPUP) > >> { > >> Name (_ADR, Zero) > >> Method (_RMV, 0, NotSerialized) > >> { > >> Return (One) > >> } > >> } > >> } > >> } > >> > >> If we want to support such machines we must look for the _RMV method a bit > >> deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check > >> few more devices down from the root port. > > > > We found that this approach is broken. We've got false positive: host > > bridge itself was detected as hotplugable slot %) I think it's not > > acceptable. > > > > Mika has tried few more approaches, but we haven't found anything better > > then hardcoded path like in original workaround patch[1]. It's not generic > > at all, but safe from false positives. > > > > Any thoughts? > > > > [1] http://article.gmane.org/gmane.linux.kernel.pci/19102 > > The changelog of this patch ([1]) says "Correct ACPI PCI hotplug > implementation should have _RMV method in a PCI slot (device under pci > bridge). In Acer Aspire S5 case we have it deeper in hierarchy ..." > > This is exactly what I mean about acpiphp being brittle because of the > assumptions it makes about the ACPI namespace. Is there actually > something in the spec that requires the _RMV method to be where > pcihp_is_ejectable() expects it? > > I'm not 100% dead-set against merging the workaround with hard-coded > path, but I still don't think it's a good idea. It "fixes" it for one > particular machine, but there will likely be other machines that > require similar fixes in the future. It makes it harder for somebody > to clean up the design later, because that person won't have an Aspire > S5 to test. It makes it less likely that somebody *will* clean it up > later, because "everything is already working." > > That's why my preference (given infinite resources) would be to rework > acpiphp now, while people are interested and can test it. Well, I have a plan to do just that, but quite frankly I'd prefer to make things physically work first and *then* to make them nicer. > I'm sure this would be a major redesign of acpiphp and its interaction with > pciehp, but I think it's something we're going to have to do at some > point. Yes, we need to do that pretty much as soon as reasonably possible, but let's not hold back changes allowing people to use their hardware with Linux because of that. We very well may need to spend a couple of releases on it. Thanks, Rafael
On Tuesday, July 02, 2013 08:45:42 PM Kirill A. Shutemov wrote: > Bjorn Helgaas wrote: > > On Tue, Jul 2, 2013 at 4:44 AM, Kirill A. Shutemov > > <kirill.shutemov@linux.intel.com> wrote: > > > Mika Westerberg wrote: > > >> The acpiphp driver finds out whether the device is hotpluggable by checking > > >> whether it has _RMV method behind it (and if it returns 1). However, at > > >> least Acer Aspire S5 with Thunderbolt host router has this method placed > > >> behind device called EPUP (endpoint upstream port?) and not directly behind > > >> the root port as can be seen from the ASL code below: > > >> > > >> Device (RP05) > > >> { > > >> ... > > >> Device (HRUP) > > >> { > > >> Name (_ADR, Zero) > > >> Name (_PRW, Package (0x02) > > >> { > > >> 0x09, > > >> 0x04 > > >> }) > > >> Device (HRDN) > > >> { > > >> Name (_ADR, 0x00040000) > > >> Name (_PRW, Package (0x02) > > >> { > > >> 0x09, > > >> 0x04 > > >> }) > > >> Device (EPUP) > > >> { > > >> Name (_ADR, Zero) > > >> Method (_RMV, 0, NotSerialized) > > >> { > > >> Return (One) > > >> } > > >> } > > >> } > > >> } > > >> > > >> If we want to support such machines we must look for the _RMV method a bit > > >> deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check > > >> few more devices down from the root port. > > > > > > We found that this approach is broken. We've got false positive: host > > > bridge itself was detected as hotplugable slot %) I think it's not > > > acceptable. > > > > > > Mika has tried few more approaches, but we haven't found anything better > > > then hardcoded path like in original workaround patch[1]. It's not generic > > > at all, but safe from false positives. > > > > > > Any thoughts? > > > > > > [1] http://article.gmane.org/gmane.linux.kernel.pci/19102 > > > > The changelog of this patch ([1]) says "Correct ACPI PCI hotplug > > implementation should have _RMV method in a PCI slot (device under pci > > bridge). In Acer Aspire S5 case we have it deeper in hierarchy ..." > > > > This is exactly what I mean about acpiphp being brittle because of the > > assumptions it makes about the ACPI namespace. Is there actually > > something in the spec that requires the _RMV method to be where > > pcihp_is_ejectable() expects it? > > Spec says that _RMV indicates the device which can be removed. > Rest, I believe, are assumptions: if the device is removable, then parent > must be a hotpluggable slot. Where "hotpluggable slot" is a very weakly defined entity. :-) _RMV means: this device only supports surprise-style removal. Moreover, it is mandatory for removable devices without _LCK or _EJx. _RMV on one device doesn't actually mean anything for other devices. > It looks reasonable, but doesn't work in this case. And it's not obvious > how we can generalize the assumption to cover the case. > > > I'm not 100% dead-set against merging the workaround with hard-coded > > path, but I still don't think it's a good idea. It "fixes" it for one > > particular machine, but there will likely be other machines that > > require similar fixes in the future. It makes it harder for somebody > > to clean up the design later, because that person won't have an Aspire > > S5 to test. It makes it less likely that somebody *will* clean it up > > later, because "everything is already working." > > > > That's why my preference (given infinite resources) would be to rework > > acpiphp now, while people are interested and can test it. I'm sure > > this would be a major redesign of acpiphp and its interaction with > > pciehp, but I think it's something we're going to have to do at some > > point. > > Basically, we run out of ideas. Any input is welcome! :) > > For now we can post new version of patchset without the workaround and > come back later with workaround (or proper solution if we'll find any). > > Does it work for you? Or you prefer everything in one patchset? Please post the current version of the patchset with as much of the feedback taken into account as possible without breaking functionality. Thanks, Rafael
diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c index 2a47e82..2760954 100644 --- a/drivers/pci/hotplug/acpi_pcihp.c +++ b/drivers/pci/hotplug/acpi_pcihp.c @@ -408,21 +408,64 @@ got_one: } EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware); +static acpi_status pcihp_evaluate_rmv(acpi_handle handle, u32 lvl, + void *context, void **return_not_used) +{ + unsigned long long *removable = context; + unsigned long long value; + acpi_status status; + + status = acpi_evaluate_integer(handle, "_RMV", NULL, &value); + if (ACPI_SUCCESS(status) && value) { + *removable = value; + return AE_CTRL_TERMINATE; + } + return AE_OK; +} + +/* + * pcihp_is_removable - check if this device is removable + * @handle: ACPI handle of the device + * @depth: how deep in the hierarchy we look for the _RMV + * + * Look for _RMV method behind the device. @depth specifies how deep in the + * hierarchy we search. + * + * Returns %true if the device is removable, %false otherwise. + */ +static bool pcihp_is_removable(acpi_handle handle, size_t depth) +{ + unsigned long long removable = 0; + acpi_status status; + + status = pcihp_evaluate_rmv(handle, 0, &removable, NULL); + if ((status == AE_CTRL_TERMINATE) && removable) + return true; + + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, depth, pcihp_evaluate_rmv, + NULL, &removable, NULL); + return !!removable; +} + +/* + * Some BIOSes, like the one in Acer Aspire S5 places the _RMV method a bit + * deeper in the hierarhcy. So check at least 3 levels behind this device. + */ +#define PCIHP_RMV_MAX_DEPTH 3 + static int pcihp_is_ejectable(acpi_handle handle) { acpi_status status; acpi_handle tmp; - unsigned long long removable; + status = acpi_get_handle(handle, "_ADR", &tmp); if (ACPI_FAILURE(status)) return 0; status = acpi_get_handle(handle, "_EJ0", &tmp); if (ACPI_SUCCESS(status)) return 1; - status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable); - if (ACPI_SUCCESS(status) && removable) - return 1; - return 0; + + return pcihp_is_removable(handle, PCIHP_RMV_MAX_DEPTH); } /**
The acpiphp driver finds out whether the device is hotpluggable by checking whether it has _RMV method behind it (and if it returns 1). However, at least Acer Aspire S5 with Thunderbolt host router has this method placed behind device called EPUP (endpoint upstream port?) and not directly behind the root port as can be seen from the ASL code below: Device (RP05) { ... Device (HRUP) { Name (_ADR, Zero) Name (_PRW, Package (0x02) { 0x09, 0x04 }) Device (HRDN) { Name (_ADR, 0x00040000) Name (_PRW, Package (0x02) { 0x09, 0x04 }) Device (EPUP) { Name (_ADR, Zero) Method (_RMV, 0, NotSerialized) { Return (One) } } } } If we want to support such machines we must look for the _RMV method a bit deeper in the hierarchy. Fix this by changing pcihp_is_ejectable() to check few more devices down from the root port. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- drivers/pci/hotplug/acpi_pcihp.c | 53 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 48 insertions(+), 5 deletions(-)