On Sun, May 14, 2017 at 03:36:56PM +0200, Alexander Sverdlin wrote: > Hello Vinod, > > On 14/05/17 15:33, Alexander Sverdlin wrote: > >>> + if (m2p_channel_nextbuf(edmac) != 0) > >>> + dev_warn(chan2dev(edmac), "M2P: Starting from BASE1\n"); > >> But then you are actually not restarting from BASE1 as you reset, so the > >> warn is wrong.. Perhaps a more meaningful msg would be to say "expected 0 > >> but found 1, so resetting" > > Should it be something like "M2P: Channel has not been reset properly!\n"? Better and with a word that you recovered and did reset of the state > > This is, maybe not so obvious, a warning, which should never fire. It just > > proves, that I understand the HW correctly. As long as nobody sees the warning, > > it's the case. And it proves that HW behaves according to user manual. > > We can remove this warning completely. > > > > Once again, the story is following: > > > > - m2p_hw_setup() is always called after channel reset > > - after reset channel expects to start from buffer 0 > > - therefore we must always start from buffer 0 <= this was not the case before > > - we can read the expected "next buffer" from the controller => hence the warning > > maybe if there will be a bug somewhere and the channel will not be reset before > > next transfer, it will be triggered > > -- > Alexander. -- ~Vinod -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
