No problems - have logged this in Bugzilla as #218143: https://bugzilla.kernel.org/show_bug.cgi?id=218143 Regards, James. On Mon, 13 Nov 2023 at 18:04, Box, David E <david.e.box@xxxxxxxxx> wrote: > > Hi James, > > Can you file a bug at https://bugzilla.kernel.org/ under Power Management? Let us know what the bug number is. Thanks. > > David > ________________________________ > From: James Hutchinson <jahutchinson99@xxxxxxxxxxxxxx> > Sent: Monday, November 13, 2023 7:42 AM > To: Pardee, Xi <xi.pardee@xxxxxxxxx>; rajneesh bhardwaj <irenic.rajneesh@xxxxxxxxx>; Box, David E <david.e.box@xxxxxxxxx>; ilpo.jarvinen@xxxxxxxxxxxxxxx <ilpo.jarvinen@xxxxxxxxxxxxxxx>; hdegoede@xxxxxxxxxx <hdegoede@xxxxxxxxxx> > Cc: platform-driver-x86@xxxxxxxxxxxxxxx <platform-driver-x86@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx> > Subject: platform/x86/intel/pmc: regression found in commit 804951203aa541ad6720c9726c173d18aeb3ab6b > > Running here on an Intel NUC 8i3BEH Coffee Lake machine under Arch Linux. > > Connected to this machine I have 4x USB DVB Cards (2xDVBSky S960 > DVB-S2 adapters & 2xGeniatech T230 DVB-T2 adapters), and I stream TV > Channels around the house via Tvheadend. > > Since linux kernel v6.5 onwards I noticed a bad performance regression > whereby the streams are basically unstable. There are tons of > continuity errors in the Tvheadend logfile, and the picture and sound > are badly broken up as though the system is throttled or does not have > the bandwidth to cope with the streams. > > Sometimes the stream will work for a minute or so after reboot, before > then becoming unstable, and then seems to remain unstable until the > next cold reboot. > > I dropped back to v6.1 LTS (where everything is fine) and re-tested > following the release of v6.6... > ...the problem had not gone away so I performed a git bisect to > identify the culprit and found this to be: > > 804951203aa541ad6720c9726c173d18aeb3ab6b: platform/x86:intel/pmc: > Combine core_init() and core_configure() > > I can work around the issue by either reverting this commit or by > disabling CONFIG_INTEL_PMC_CORE and rebuilding the kernel manually, > either of which results in perfect DVB streaming once more. > > Happy to test any potential patches or otherwise provide further > information as required. > > > James.
