Hi All, > -----Original Message----- > From: Michael Auchter <michael.auchter@xxxxxx> > Sent: Tuesday, October 6, 2020 3:21 PM > To: Ben Levinsky <BLEVINSK@xxxxxxxxxx> > Cc: Ed T. Mooring <emooring@xxxxxxxxxx>; Stefano Stabellini > <stefanos@xxxxxxxxxx>; Michal Simek <michals@xxxxxxxxxx>; > devicetree@xxxxxxxxxxxxxxx; mathieu.poirier@xxxxxxxxxx; linux- > remoteproc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > robh+dt@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: RE: RE: [PATCH v18 5/5] remoteproc: Add initial zynqmp R5 > remoteproc driver > > On Tue, Oct 06, 2020 at 09:46:38PM +0000, Ben Levinsky wrote: > > > > > > > -----Original Message----- > > > From: Michael Auchter <michael.auchter@xxxxxx> > > > Sent: Tuesday, October 6, 2020 2:32 PM > > > To: Ben Levinsky <BLEVINSK@xxxxxxxxxx> > > > Cc: Ed T. Mooring <emooring@xxxxxxxxxx>; sunnyliangjy@xxxxxxxxx; > > > punit1.agrawal@xxxxxxxxxxxxx; Stefano Stabellini <stefanos@xxxxxxxxxx>; > > > Michal Simek <michals@xxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; > > > mathieu.poirier@xxxxxxxxxx; linux-remoteproc@xxxxxxxxxxxxxxx; linux- > > > kernel@xxxxxxxxxxxxxxx; robh+dt@xxxxxxxxxx; linux-arm- > > > kernel@xxxxxxxxxxxxxxxxxxx > > > Subject: Re: RE: [PATCH v18 5/5] remoteproc: Add initial zynqmp R5 > > > remoteproc driver > > > > > > On Tue, Oct 06, 2020 at 07:15:49PM +0000, Ben Levinsky wrote: > > > > > > > > Hi Michael, > > > > > > > > Thanks for the review > > > > > > > > > > < ... snip ... > > > > > > > > > > + z_rproc = rproc->priv; > > > > > > + z_rproc->dev.release = zynqmp_r5_release; > > > > > > > > > > This is the only field of z_rproc->dev that's actually initialized, and > > > > > this device is not registered with the core at all, so zynqmp_r5_release > > > > > will never be called. > > > > > > > > > > Since it doesn't look like there's a need to create this additional > > > > > device, I'd suggest: > > > > > - Dropping the struct device from struct zynqmp_r5_rproc > > > > > - Performing the necessary cleanup in the driver remove > > > > > callback instead of trying to tie it to device release > > > > > > > > For the most part I agree. I believe the device is still needed for > > > > the mailbox client setup. > > > > > > > > As the call to mbox_request_channel_byname() requires its own device > > > > that has the corresponding child node with the corresponding > > > > mbox-related properties. > > > > > > > > With that in mind, is it still ok to keep the device node? > > > > > > Ah, I see. Thanks for the clarification! > > > > > > Instead of manually dealing with the device node creation for the > > > individual processors, perhaps it makes more sense to use > > > devm_of_platform_populate() to create them. This is also consistent with > > > the way the TI K3 R5F remoteproc driver does things. > > > > > > Cheers, > > > Michael > > > > I've been working on this today for a way around it and found one that I > think works with your initial suggestion, > > - in z_rproc, change dev from struct device to struct device* > > ^ the above is shown the usage thereof below. It is there for the > mailbox setup. > > - in driver probe: > > - add list_head to keep track of each core's z_rproc and for the driver > remove clean up > > - in each core's probe (zynqmp_r5_probe) dothe following: > > > > > > rproc_ptr = rproc_alloc(dev, dev_name(dev), &zynqmp_r5_rproc_ops, > > NULL, sizeof(struct zynqmp_r5_rproc)); > > if (!rproc_ptr) > > return -ENOMEM; > > z_rproc = rproc_ptr->priv; > > z_rproc->dt_node = node; > > z_rproc->rproc = rproc_ptr; > > z_rproc->dev = &rproc_ptr->dev; > > z_rproc->dev->of_node = node; > > where node is the specific R5 core's of_node/ Device tree node. > > > > the above preserves most of the mailbox setup code. > > I see how this works, but it feels a bit weird to me to be overriding > the remoteproc dev's of_node ptr. Personally I find the > devm_of_platform_populate() approach a bit less confusing. > > But, it's also not my call to make ;). Perhaps a remoteproc maintainer > can chime in here. > > > Ping for comments here. I looked at the TI R5 remoteproc driver and from what I can see, it seems the crux of the line: z_rproc->dev->of_node = node; is as follows: the TI driver only has 1 R5-related remoteproc node. But in this it has information for both cores so the rproc_alloc's device that is passed in is sufficient for subsequent mailbox calls. This is because the device here also has a device_node that has the mbox information. The Xilinx driver differs in that while there is a cluster device tree node that has the remoteproc-related Information, it ALSO has child R5 cores that have their own TCM bank and mbox information. As a result of this difference the use of devm_of_populate would not remove the use of the line of code in question because the mailbox setup calls later on still require the device field to have a corresponding device tree node that Has the mailbox information. If it is desired to see the use of devm_of_populate and more close alignment to the TI driver that has been merged then the Xilinx R5 driver bindings can instead have the TCM bank info, memory-regions, meta-memory-regions into R5 core-specific lists which resembles how the TI R5 driver has R5 core-specific properties. At this point just trying to suss out some direction in this patch series. Your feedback and review is much appreciated, Ben > > > > With this, I have already successfully done the following in a v19 patch > > - move all the previous driver release code to remove > > - able to probe, start/stop r5, driver remove repeatedly > > > > Also, this mimics the TI R5 driver code as each core's rproc has a list_head > and they have a structure for the cluster which among other things maintains > a linked list of the cores' specific rproc information. > > > > Thanks > > Ben
