Messages in this thread | | | Date | Mon, 8 Jun 2020 12:16:19 +0100 | From | Mark Brown <> | Subject | Re: [PATCH 4.19 15/28] spi: dw: use "smp_mb()" to avoid sending spi data error |
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On Sun, Jun 07, 2020 at 10:09:11PM +0200, Pavel Machek wrote:
> > Because of out-of-order execution about some CPU architecture, > > In this debug stage we find Completing spi interrupt enable -> > > prodrucing TXEI interrupt -> running "interrupt_transfer" function > > will prior to set "dw->rx and dws->rx_end" data, so this patch add > > memory barrier to enable dw->rx and dw->rx_end to be visible and > > solve to send SPI data error.
> So, this is apparently CPU-vs-device issue...
The commit message is a bit unclear but my read had been interrupt handler racing with sending new data rather than an ordering issue with writes to the hardware. [unhandled content-type:application/pgp-signature] | |