No description
03937391bc
There are a lot errors reported by AER driver for root port 0.
The erors are being caused by an unsupported request from the
device to the upstream port. Enabling LTR on the root port stops
these errors, it is because LTR is enabled on the device side but
not on the root port and hence root port was logging the LTR messages
from the device as unsupported.
The PCIe base spec (v3.1a) section 6.18 also states that:
LTR support is discovered and enabled through reporting and control
registers described in Chapter 7. Software must not enable LTR in an
Endpoint unless the Root Complex and all intermediate Switches indicate
support for LTR. Note that it is not required that all Endpoints support
LTR to permit enabling LTR in those Endpoints that do support it. When
enabling the LTR mechanism in a hierarchy, devices closest to the
Root Port must be enabled first.
If an LTR Message is received at a Downstream Port that does not
support LTR or if LTR is not enabled, the Message must be treated
as an Unsupported Request. FSP has a UPD for enabling/disabling
LTR on root port, use the same for configuring LTR on PCIe root ports.
BUG=b:65570878
TEST=After enbaling LTR on port 0 on the MB devicetree, No errors reported
by AER driver for root port 0.
Change-Id: Ica97faa78fcd991dad63ae54d2ada82194b4202a
Signed-off-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Reviewed-on: https://review.coreboot.org/21547
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
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| configs | ||
| Documentation | ||
| payloads | ||
| src | ||
| util | ||
| .checkpatch.conf | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| .gitreview | ||
| COPYING | ||
| gnat.adc | ||
| MAINTAINERS | ||
| Makefile | ||
| Makefile.inc | ||
| README | ||
| toolchain.inc | ||
------------------------------------------------------------------------------- coreboot README ------------------------------------------------------------------------------- coreboot is a Free Software project aimed at replacing the proprietary BIOS (firmware) found in most computers. coreboot performs a little bit of hardware initialization and then executes additional boot logic, called a payload. With the separation of hardware initialization and later boot logic, coreboot can scale from specialized applications that run directly firmware, run operating systems in flash, load custom bootloaders, or implement firmware standards, like PC BIOS services or UEFI. This allows for systems to only include the features necessary in the target application, reducing the amount of code and flash space required. coreboot was formerly known as LinuxBIOS. Payloads -------- After the basic initialization of the hardware has been performed, any desired "payload" can be started by coreboot. See https://www.coreboot.org/Payloads for a list of supported payloads. Supported Hardware ------------------ coreboot supports a wide range of chipsets, devices, and mainboards. For details please consult: * https://www.coreboot.org/Supported_Motherboards * https://www.coreboot.org/Supported_Chipsets_and_Devices Build Requirements ------------------ * make * gcc / g++ Because Linux distribution compilers tend to use lots of patches. coreboot does lots of "unusual" things in its build system, some of which break due to those patches, sometimes by gcc aborting, sometimes - and that's worse - by generating broken object code. Two options: use our toolchain (eg. make crosstools-i386) or enable the ANY_TOOLCHAIN Kconfig option if you're feeling lucky (no support in this case). * iasl (for targets with ACPI support) * pkg-config * libssl-dev (openssl) Optional: * doxygen (for generating/viewing documentation) * gdb (for better debugging facilities on some targets) * ncurses (for 'make menuconfig' and 'make nconfig') * flex and bison (for regenerating parsers) Building coreboot ----------------- Please consult https://www.coreboot.org/Build_HOWTO for details. Testing coreboot Without Modifying Your Hardware ------------------------------------------------ If you want to test coreboot without any risks before you really decide to use it on your hardware, you can use the QEMU system emulator to run coreboot virtually in QEMU. Please see https://www.coreboot.org/QEMU for details. Website and Mailing List ------------------------ Further details on the project, a FAQ, many HOWTOs, news, development guidelines and more can be found on the coreboot website: https://www.coreboot.org You can contact us directly on the coreboot mailing list: https://www.coreboot.org/Mailinglist Copyright and License --------------------- The copyright on coreboot is owned by quite a large number of individual developers and companies. Please check the individual source files for details. coreboot is licensed under the terms of the GNU General Public License (GPL). Some files are licensed under the "GPL (version 2, or any later version)", and some files are licensed under the "GPL, version 2". For some parts, which were derived from other projects, other (GPL-compatible) licenses may apply. Please check the individual source files for details. This makes the resulting coreboot images licensed under the GPL, version 2.