On Tue, Jul 31, 2018 at 3:45 PM, Jassi Brar <jassisinghbrar@xxxxxxxxx> wrote: > On Tue, Jul 31, 2018 at 12:51 PM, A.s. Dong <aisheng.dong@xxxxxxx> wrote: >> Hi Jassi, >> >>> > However, if SCU (in its current form) must be supported. We may need >>> > to add the third cell (irq enable or not) or some better way, right >>> > now. >>> > >>> Looking at imx_mu_scu_send_data(), which simply polls on the tx, I think we >>> don't even need third cell for scu client. A simple 2-cell, 8 uni-dir channel >>> setup should work. >> >> How would you suggest to use for SCU in 2 -cells? >> >>> If I see the scu client driver, I could confirm how it would work. >>> >> >> I've already given a general overview from here: >> https://www.spinics.net/lists/arm-kernel/msg669202.html >> > No, that is controller side code. > >> Do you need me to send the full scu client driver patch for the reference? >> If yes, please feel free to let me know. >> > Yes, that'll make it clearer. > Thanks for sharing the patch offline. I don't see why it can't be adapted to work with the simple 2-cell implementation. Instead of one virtual, ask for 4 physical channels and send data in u32 chunks sequentially over them. In fact, that should make it even better by removing the tight-loop (zero delay!!) polling in send_data() -- MU does support interrupts, why not use them to avoid polling? If you find it hard, I can make a patch on top of your client patchset, once Oleksij is done with the MU driver. I have some more suggestions for the client driver. But since I don't have to live with them (you do), I can't demand you make those changes. If you like, please feel free to cc me on the next revision of the client driver. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
