17.09.2020 14:47, Thierry Reding пишет: > On Wed, Sep 09, 2020 at 01:39:53AM +0300, Dmitry Osipenko wrote: >> The DMA code path has been tested well enough and the DMA configuration >> performed by tegra_i2c_config_fifo_trig() shouldn't ever fail in practice. >> Hence let's remove the obscure transfer-mode switching in order to have a >> cleaner and simpler code. Now I2C transfer will be failed if DMA >> configuration fails. >> >> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> >> --- >> drivers/i2c/busses/i2c-tegra.c | 18 ++++++++++-------- >> 1 file changed, 10 insertions(+), 8 deletions(-) > > I'm not sure that's a good idea. It's always possible that the DMA setup > is going to break because of something that's not related to the I2C > driver itself. Having the system completely break instead of falling > back to PIO mode seems like it would only complicate troubleshooting any > such issues. That code has zero test coverage because this problem never happens in practice, hence it should be better to have it removed. We may consider re-adding it back if there will be a real-world incident, okay?