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kitakar5525 / chromeos-kernel-linux-surface

linux-surface kernel for chromiumos.
GNU General Public License v3.0
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chromeos-4.19: can't enable DMA for surface3-spi #22

Open kitakar5525 opened 4 years ago

kitakar5525 commented 4 years ago

surface3-spi uses PIO on both general and minimal config on chromeos-4.19 by default. Why?

$ echo "file drivers/spi/spi-pxa2xx.c +p" | sudo tee /sys/kernel/debug/dynamic_debug/control
$ dmesg -xw # then make a touch input
kern  :debug : [  446.556454] Surface3-spi spi-MSHW0037:00: 7692307 Hz actual, PIO

It uses DMA by default on chromeos-5.4 with both general and minimal config.