Hi, Am 30.09.20 um 18:38 schrieb Nathan Chancellor: > On Wed, Sep 30, 2020 at 04:07:58PM +0200, Maxime Ripard wrote: >> Hi Nathan, >> >> On Tue, Sep 29, 2020 at 03:15:26PM -0700, Nathan Chancellor wrote: >>> On Thu, Sep 03, 2020 at 10:01:52AM +0200, Maxime Ripard wrote: >>>> Now that all the drivers have been adjusted for it, let's bring in the >>>> necessary device tree changes. >>>> >>>> The VEC and PV3 are left out for now, since it will require a more specific >>>> clock setup. >>>> >>>> Reviewed-by: Dave Stevenson <dave.steven...@raspberrypi.com> >>>> Tested-by: Chanwoo Choi <cw00.c...@samsung.com> >>>> Tested-by: Hoegeun Kwon <hoegeun.k...@samsung.com> >>>> Tested-by: Stefan Wahren <stefan.wah...@i2se.com> >>>> Signed-off-by: Maxime Ripard <max...@cerno.tech> >>> Apologies if this has already been reported or have a solution but this >>> patch (and presumably series) breaks output to the serial console after >>> a certain point during init. On Raspbian, I see systemd startup messages >>> then the output just turns into complete garbage. It looks like this >>> patch is merged first in linux-next, which is why my bisect fell on the >>> DRM merge. I am happy to provide whatever information could be helpful >>> for debugging this. I am on the latest version of the firmware >>> (currently 26620cc9a63c6cb9965374d509479b4ee2c30241). >> Unfortunately, the miniUART is in the same clock tree than the core >> clock and will thus have those kind of issues when the core clock is >> changed (which is also something that one should expect when using the >> DRM or other drivers). >> >> The only real workaround there would be to switch to one of the PL011 >> UARTs. I guess we can also somehow make the UART react to the core clock >> frequency changes, but that's going to require some effort >> >> Maxime > Ack, thank you for the reply! There does not really seem to be a whole > ton of documentation around using one of the other PL011 UARTs so for > now, I will just revert this commit locally.
there was a patch series & discussion about this topic, but we finally didn't find a rock solid solution. You can have a look at "[RFC 5/5] serial: 8250: bcm2835aux: add notifier to follow clock changes" from 3.4.2019 on linux-rpi-kernel. Best regards > > Cheers, > Nathan _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
