lkml.org 
[lkml]   [2019]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 3/9] PCI/ACPI: Expose EDR support via _OSC to BIOS
On Fri, Jul 26, 2019 at 02:43:13PM -0700, sathyanarayanan.kuppuswamy@linux.intel.com wrote:
> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>
> As per PCI firmware specification r3.2 Downstream Port Containment
> Related Enhancements ECN, sec 4.5.1, table 4-4, if OS supports EDR,
> it should expose its support to BIOS by setting bit 7 of _OSC Support
> Field.
>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Len Brown <lenb@kernel.org>
> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> ---
> drivers/acpi/pci_root.c | 3 +++
> include/linux/acpi.h | 1 +
> 2 files changed, 4 insertions(+)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 73b08f40b0da..988d09d788b6 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -132,6 +132,7 @@ static struct pci_osc_bit_struct pci_osc_support_bit[] = {
> { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
> { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
> { OSC_PCI_MSI_SUPPORT, "MSI" },
> + { OSC_PCI_EDR_SUPPORT, "EDR" },
> { OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
> };
>
> @@ -442,6 +443,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
> support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
> if (pci_msi_enabled())
> support |= OSC_PCI_MSI_SUPPORT;
> + if (IS_ENABLED(CONFIG_PCIE_EDR))
> + support |= OSC_PCI_EDR_SUPPORT;

Do we really support it here? This is patch [3/9] and it looks like
patch [6/9] might be where EDR support really gets added. It's good
to split changes into small pieces, but only if each piece is
logically self-contained.

> decode_osc_support(root, "OS supports", support);
> status = acpi_pci_osc_support(root, support);
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 8959ed322e15..b6b43da85d26 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -515,6 +515,7 @@ extern bool osc_pc_lpi_support_confirmed;
> #define OSC_PCI_CLOCK_PM_SUPPORT 0x00000004
> #define OSC_PCI_SEGMENT_GROUPS_SUPPORT 0x00000008
> #define OSC_PCI_MSI_SUPPORT 0x00000010
> +#define OSC_PCI_EDR_SUPPORT 0x00000080
> #define OSC_PCI_HPX_TYPE_3_SUPPORT 0x00000100
> #define OSC_PCI_SUPPORT_MASKS 0x0000011f

You defined a new bit above but didn't update OSC_PCI_SUPPORT_MASKS to
include that bit. This looks broken.

\
 
 \ /
  Last update: 2019-08-16 00:29    [W:0.118 / U:2.600 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site