On Mon, Mar 28, 2016 at 7:32 PM, Joachim Eastwood <manabian@xxxxxxxxx> wrote: > On 26 March 2016 at 00:51, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: >> Joachim: Can you please help to try to figure out if this >> still crashes with LPC, it must be something with the mux >> layer thing. This is doing the right thing and is needed >> for atleast 2 platforms to use this driver. > > First of all; sorry about the screw up with the attempt to do dynamic > channel allocation in the xlate. As Linus noted in [1] the dmaengine > framework doesn't support this as channels are not initialized > properly and it only seemed to work properly because of the mux. Sorry > about all this! Hey we all make mistakes. More often than not, it's actually me. > Note the LPC18xx didn't really crash with this patch. It was only > unable to find the dma channels [2]. When the initial patches was > posted I didn't have the time to debug it properly and I have since > forgotten about it. > > The reason for this, as discovered by Johannes [3], is that > chan->signal is not properly setup. This variable is set to -1 in > pl08x_dma_init_virtual_channels() and when pl08x_find_chan_id() is > called from xlate it doesn't find any channels because the chan->id is > still -1 (I have verified this with debug prints). Setting chan->id > make the channel assignment work on LPC18xx again. OK I think what you mean is that chan->signal must be assigned by default so the channel can me found? This should be fixed with the v3 patch I just sent out. I hope. > Linus: Could you send an updated version that sets the chan->id > variable in pl08x_dma_init_virtual_channels()? chan->signal you mean? Enjoy! Else comment inline in the patch exactly what I need to do. > Maybe it would make sense to reorder the patches since this patch is a fix. Nah I just dropped the first one as Johannes suggested. It's down to one now. Tested on the Nomadik, works like a charm. Yours, Linus Walleij -- 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
