* Frans Klaver | 2014-09-29 11:26:06 [+0200]: >On Wed, Sep 10, 2014 at 09:30:08PM +0200, Sebastian Andrzej Siewior wrote: >> There is nothing to do for RPM in the RX path. If the HW goes off then it >> won't assert the DMA line and the transfer won't happen. So we hope that >> the HW does not go off for RX to work (DMA or PIO makes no difference >> here). >> >> For TX the situation is slightly different. RPM is enabled on >> start_tx(). We can't disable RPM on DMA complete callback because there >> is still data in the FIFO which is being sent. We have to wait until >> the FIFO is empty before we disable it. >> For this to happen we fake a TX sent error and enable THRI. Once the >> FIFO is empty we receive an interrupt and since the TTY-buffer is still >> empty we "put RPM" via __stop_tx(). Should it been filed then in the >> start_tx() path we should program the DMA transfer and remove the error >> flag and the THRI bit. > >That last sentence starts out a bit messy. This got mered so there is nothing I can do about it anymore. But I will try to fix comments in code where and in patches that are not yet merged (what you report :)) Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
