Den 05.09.2022 16.57, skrev Maxime Ripard: > On Fri, Sep 02, 2022 at 01:28:16PM +0200, Noralf Trønnes wrote: >> >> >> Den 01.09.2022 21.35, skrev Noralf Trønnes: >>> >>> >>> I have finally found a workaround for my kernel hangs. >>> >>> Dom had a look at my kernel and found that the VideoCore was fine, and >>> he said this: >>> >>>> That suggests cause of lockup was on arm side rather than VC side. >>>> >>>> But it's hard to diagnose further. Once you've had a peripheral not >>>> respond, the AXI bus locks up and no further operations are possible. >>>> Usual causes of this are required clocks being stopped or domains >>>> disabled and then trying to access the hardware. >>>> >>> >>> So when I got this on my 64-bit build: >>> >>> [ 166.702171] SError Interrupt on CPU1, code 0x00000000bf000002 -- SError >>> [ 166.702187] CPU: 1 PID: 8 Comm: kworker/u8:0 Tainted: G W >>> 5.19.0-rc6-00096-gba7973977976-dirty #1 >>> [ 166.702200] Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT) >>> [ 166.702206] Workqueue: events_freezable_power_ thermal_zone_device_check >>> [ 166.702231] pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS >>> BTYPE=--) >>> [ 166.702242] pc : regmap_mmio_read32le+0x10/0x28 >>> [ 166.702261] lr : regmap_mmio_read+0x44/0x70 >>> ... >>> [ 166.702606] bcm2711_get_temp+0x58/0xb0 [bcm2711_thermal] >>> >>> I wondered if that reg read was stalled due to a clock being stopped. >>> >>> Lo and behold, disabling runtime pm and keeping the vec clock running >>> all the time fixed it[1]. >>> >>> I don't know what the problem is, but at least I can now test this patchset. >>> >>> [1] https://gist.github.com/notro/23b984e7fa05cfbda2db50a421cac065 >>> >> >> It turns out I didn't have to disable runtime pm: >> https://gist.github.com/notro/0adcfcb12460b54e54458afe11dc8ea2 > > If the bcm2711_thermal IP needs that clock to be enabled, it should grab > a reference itself, but it looks like even the device tree binding > doesn't ask for one. > The first thing I tried was to unload the bcm2711_thermal module before running modeset and it still hung, so I don't think that's the problem. Noralf.