[PATCH] arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES)

[Mark Rutland]

On Mon, Jun 07, 2021 at 11:58:32AM +0200, Marek Szyprowski wrote:
> Hi Mark,

> I've just checked with the latest firmware from 
> https://github.com/raspberrypi/firmware (master branch, just copied 
> everything to /boot) and the issue is still there.
> 
> If you start from arm64/defconfig without modules, please make sure you 
> have enabled all RPi drivers, otherwise VC4 DRM won't come up. I've 
> managed to reproduce the issue without the modules with the following 
> changes to arm64's defconfig:
> 
> ./scripts/config -e DRM -e DRM_VC4 -e CONFIG_CLK_RASPBERRYPI -e 
> CONFIG_SENSORS_RASPBERRYPI_HWMON -e CONFIG_I2C_BCM2835 -e 
> CONFIG_ARM_RASPBERRYPI_CPUFREQ

Thanks for this!

With that config on commit 65688d2a05deb9f0 I also see a hang at the end
of boot, but before reaching userspace, with the last messages in dmesg
as below.

I'll go check that the ARCH_DMA_MINALIGN affects this, then I'll go play
with debug options.

| [    1.397102] 3f201000.serial: ttyAMA0 at MMIO 0x3f201000 (irq = 99, base_baud = 0) is a PL011 rev2
| [    1.406437] serial serial0: tty port ttyAMA0 registered
| [    1.408914] sdhost-bcm2835 3f202000.mmc: loaded - DMA enabled (>1)
| [    1.430510] raspberrypi-firmware soc:firmware: Attached to firmware from 2021-05-24T19:52:58
| [    1.504953] mmc0: host does not support reading read-only switch, assuming write-enable
| [    1.514908] mmc0: new high speed SDXC card at address 0001
| [    1.521626] mmcblk0: mmc0:0001 00000 59.6 GiB
| [    1.528406]  mmcblk0: p1 p2
| [    1.644694] debugfs: Directory '3f902000.hdmi' with parent 'vc4-hdmi' already present!
| [    1.654544] vc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops)
| [    1.661078] vc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops)
| [    1.667401] vc4-drm soc:gpu: bound 3f400000.hvs (ops vc4_hvs_ops)
| [    1.673760] vc4-drm soc:gpu: bound 3f004000.txp (ops vc4_txp_ops)
| [    1.680096] vc4-drm soc:gpu: bound 3f206000.pixelvalve (ops vc4_crtc_ops)
| [    1.687157] vc4-drm soc:gpu: bound 3f207000.pixelvalve (ops vc4_crtc_ops)
| [    1.694172] vc4-drm soc:gpu: bound 3f807000.pixelvalve (ops vc4_crtc_ops)
| [    1.701170] vc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops)
| [    1.709277] [drm] Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0

Thanks,
Mark.