Hi Janusz, > Users of Intel discrete graphics adapters are confused with fake > information on PCIe link bandwidth (speed and size) of their GPU devices > reported by tools like lspci or lsgpu. That fake information is > unfortunately provided by hardware, Linux PCI subsystem just exposes it > untouched to upper layers, including userspace via sysfs, and userspace > tools just report those fake values. > > While we can't do much about the kernel side or general purpose userspace > tools like lspci, we can try to address the issue with our lsgpu utility. > > Correct link bandwidth attributes of a discrete GPU card can be obtained > from the kernel by looking not at the PCI device of the GPU itself, only > at a PCIe upstream port of the card's PCI bridge. For integrity with > content of the sysfs and with output from the other tools, we are not > going to replace the fake information with that from the bridge upstream > port, only show that port and its attributes themselves while listing > devices. > > Since the tool uses our udev based igt_device_scan library for identifying > GPU devices and printing their properties and attributes, modifications > that we need apply to that library. > > As a first step, exclude the fake data from being printed. > > v2: Keep dump_props_and_attrs() generic: hand over decision on omitting > link attributes to the caller, and implementation of the check to a > helper (Sebastian). > > Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/10753 > Cc: Sebastian Brzezinka <[email protected]> > Signed-off-by: Janusz Krzysztofik <[email protected]> > ---
I mistakenly commented on your v2, so I'll repeat it here: Reviewed-by: Krzysztof Karas <[email protected]> -- Best Regards, Krzysztof
