Ping for code review, please? It would be nice if our 'raspi3' model for 2.12 was one we could say actually booted a known Linux image...
thanks -- PMM On 19 March 2018 at 16:15, Peter Maydell <peter.mayd...@linaro.org> wrote: > This patchset fixes the code in the bcm2835_sdhost device > so that it raises interrupts in more plausible places. > > The Linux bcm2835_sdhost driver doesn't work on QEMU at the moment, > because our model raises spurious data interrupts. Our function > bcm2835_sdhost_fifo_run() will flag an interrupt any time it is > called with s->datacnt == 0, even if the host hasn't actually issued > a data read or write command yet. This means that the driver gets a > spurious data interrupt as soon as it enables IRQs and then does > something else that causes us to call the fifo_run routine, like > writing to SDHCFG, and before it does the write to SDCMD to issue the > read. The driver's IRQ handler then spins forever complaining that > there's no data and the SD controller isn't in a state where there's > going to be any data: > > [ 41.040738] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000 > [ 41.042059] sdhost-bcm2835 3f202000.mmc: fsm 1, hsts 00000000 > (continues forever). > > Move the interrupt flag setting to more plausible places: > * for BUSY, raise this as soon as a BUSYWAIT command has executed > * for DATA, raise this when the FIFO has any space free (for a write) > or any data in it (for a read) > * for BLOCK, raise this when the data count is 0 and we've > actually done some reading or writing > > This is pure guesswork since the documentation for this hardware is > not public, but it is sufficient to get the Linux bcm2835_sdhost > driver to work. > > If anybody has other OSes than Linux that use the sdhost SD > controller (not the 'Arasan' one, which is a different bit of > the SoC) testing with those would be appreciated. If anybody > has documentation for this hardware that would be even better. > > With these patches plus the previous set, I can get the Debian > raspi3 image to boot (though there are a lot of warnings relating > to the pl011 UART for some reason). > > thanks > -- PMM > > Peter Maydell (2): > hw/sd/bcm2835_sdhost: Add tracepoints > hw/sd/bcm2835_sdhost: Don't raise spurious interrupts > > hw/sd/bcm2835_sdhost.c | 51 > +++++++++++++++++++++++++++++++------------------- > hw/sd/trace-events | 6 ++++++ > 2 files changed, 38 insertions(+), 19 deletions(-) > > -- > 2.16.2
