| Message ID | 1449199466-6081-9-git-send-email-annie.wang@amd.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Fri, Dec 04, 2015 at 11:24:25AM +0800, Wang Hongcheng wrote: > From: Wan Zongshun <Vincent.Wan@amd.com> > > Add ivrs_acpihid kernel parameter description, > like ivrs_acpihid[00:14.5]=AMD0020:0. > > Signed-off-by: Wan Zongshun <Vincent.Wan@amd.com> > --- > Documentation/kernel-parameters.txt | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 742f69d..5c364c6 100644 > --- a/Documentation/kernel-parameters.txt > +++ b/Documentation/kernel-parameters.txt > @@ -1680,6 +1680,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. > PCI device 00:14.0 write the parameter as: > ivrs_hpet[0]=00:14.0 > > + ivrs_acpihid [HW,X86_64] > + Provide an override to the ACPI-HID:UID<->DEVICE-ID > + mapping provided in the IVRS ACPI table. For > + example, to map UART-HID:UID AMD0020:0 to > + PCI device 00:14.5 write the parameter as: > + ivrs_acpihid[00:14.5]=AMD0020:0 What is that parameter needed for? Can't you deduce the mapping from the hardware?
> > + ivrs_acpihid [HW,X86_64] > > + Provide an override to the ACPI-HID:UID<->DEVICE-ID > > + mapping provided in the IVRS ACPI table. For > > + example, to map UART-HID:UID AMD0020:0 to > > + PCI device 00:14.5 write the parameter as: > > + ivrs_acpihid[00:14.5]=AMD0020:0 > > What is that parameter needed for? Can't you deduce the mapping from the > hardware? It is very like ivrs_ioapic/ ivrs_hpet, which can override the dedicated BDF id mapped to HID:UID that was reported from BIOS's IVHD entry. If BIOS did not report a right BDF, we can resort to this parameter to correct it. > > -- > Regards/Gruss, > Boris. > > ECO tip #101: Trim your mails when you reply.
On Fri, Dec 04, 2015 at 01:19:35PM +0000, Wan, Vincent wrote: > > > + ivrs_acpihid [HW,X86_64] > > > + Provide an override to the ACPI-HID:UID<->DEVICE-ID > > > + mapping provided in the IVRS ACPI table. For > > > + example, to map UART-HID:UID AMD0020:0 to > > > + PCI device 00:14.5 write the parameter as: > > > + ivrs_acpihid[00:14.5]=AMD0020:0 > > > > What is that parameter needed for? Can't you deduce the mapping from the > > hardware? > > It is very like ivrs_ioapic/ ivrs_hpet, which can override the dedicated BDF id mapped to HID:UID that was reported from BIOS's IVHD entry. > If BIOS did not report a right BDF, we can resort to this parameter to correct it. Please add a verbose, human-readable explanation to the text so that people know what it is for. The text above is hard to parse even for insiders.
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 742f69d..5c364c6 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1680,6 +1680,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. PCI device 00:14.0 write the parameter as: ivrs_hpet[0]=00:14.0 + ivrs_acpihid [HW,X86_64] + Provide an override to the ACPI-HID:UID<->DEVICE-ID + mapping provided in the IVRS ACPI table. For + example, to map UART-HID:UID AMD0020:0 to + PCI device 00:14.5 write the parameter as: + ivrs_acpihid[00:14.5]=AMD0020:0 + js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt.