On Mon, Sep 05, 2022 at 05:17:18PM +0200, Noralf Trønnes wrote: > 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. Ack. Just to confirm, is this happening on mainline or on the downstream tree? Maxime
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