On 08/20/2018 09:18 AM, Bin Meng wrote: > Hi Marek, > > On Fri, Aug 17, 2018 at 6:27 PM, Marek Vasut <marek.va...@gmail.com> wrote: >> On 08/17/2018 03:51 AM, Bin Meng wrote: >>> Hi Marek, >>> >>> On Thu, Aug 16, 2018 at 7:47 PM, Marek Vasut <marek.va...@gmail.com> wrote: >>>> On 08/15/2018 01:25 PM, Tom Rini wrote: >>>>> On Wed, Aug 15, 2018 at 06:19:25PM +0800, Bin Meng wrote: >>>>>> Hi Marek, >>>>>> >>>>>> On Wed, Aug 15, 2018 at 5:22 PM, Marek Vasut <marek.va...@gmail.com> >>>>>> wrote: >>>>>>> On 08/14/2018 11:40 AM, Bin Meng wrote: >>>>>>>> Hi Marek, >>>>>>>> >>>>>>>> On Tue, Aug 14, 2018 at 4:55 PM, Marek Vasut <marek.va...@gmail.com> >>>>>>>> wrote: >>>>>>>>> On 08/14/2018 03:46 AM, Bin Meng wrote: >>>>>>>>>> Hi Marek, >>>>>>>>>> >>>>>>>>>> On Mon, Aug 13, 2018 at 9:46 PM, Marek Vasut <marek.va...@gmail.com> >>>>>>>>>> wrote: >>>>>>>>>>> On 08/13/2018 04:24 AM, Bin Meng wrote: >>>>>>>>>>>> Hi Marek, >>>>>>>>>>>> >>>>>>>>>>>> On Fri, Aug 10, 2018 at 8:38 PM, Marek Vasut >>>>>>>>>>>> <marek.va...@gmail.com> wrote: >>>>>>>>>>>>> On 08/10/2018 02:01 PM, Tom Rini wrote: >>>>>>>>>>>>>> On Wed, Aug 08, 2018 at 09:37:25PM +0200, Marek Vasut wrote: >>>>>>>>>>>>>>> On 08/08/2018 05:32 PM, Bin Meng wrote: >>>>>>>>>>>>>>>> Hi Marek, >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> On Wed, Aug 8, 2018 at 10:33 PM, Marek Vasut >>>>>>>>>>>>>>>> <marek.va...@gmail.com> wrote: >>>>>>>>>>>>>>>>> On 08/08/2018 03:39 PM, Bin Meng wrote: >>>>>>>>>>>>>>>>>> Hi Marek, >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> On Wed, Aug 8, 2018 at 9:24 PM, Marek Vasut >>>>>>>>>>>>>>>>>> <marek.va...@gmail.com> wrote: >>>>>>>>>>>>>>>>>>> On 08/08/2018 03:14 PM, Bin Meng wrote: >>>>>>>>>>>>>>>>>>>> Hi Marek, >>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>> On Wed, Aug 8, 2018 at 9:03 PM, Marek Vasut >>>>>>>>>>>>>>>>>>>> <marek.va...@gmail.com> wrote: >>>>>>>>>>>>>>>>>>>>> The PCI controller can have DT subnodes describing extra >>>>>>>>>>>>>>>>>>>>> properties >>>>>>>>>>>>>>>>>>>>> of particular PCI devices, ie. a PHY attached to an EHCI >>>>>>>>>>>>>>>>>>>>> controller >>>>>>>>>>>>>>>>>>>>> on a PCI bus. This patch parses those DT subnodes and >>>>>>>>>>>>>>>>>>>>> assigns a node >>>>>>>>>>>>>>>>>>>>> to the PCI device instance, so that the driver can >>>>>>>>>>>>>>>>>>>>> extract details >>>>>>>>>>>>>>>>>>>>> from that node and ie. configure the PHY using the PHY >>>>>>>>>>>>>>>>>>>>> subsystem. >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> Signed-off-by: Marek Vasut <marek.vasut+rene...@gmail.com> >>>>>>>>>>>>>>>>>>>>> Cc: Simon Glass <s...@chromium.org> >>>>>>>>>>>>>>>>>>>>> --- >>>>>>>>>>>>>>>>>>>>> drivers/pci/pci-uclass.c | 14 ++++++++++++++ >>>>>>>>>>>>>>>>>>>>> 1 file changed, 14 insertions(+) >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> diff --git a/drivers/pci/pci-uclass.c >>>>>>>>>>>>>>>>>>>>> b/drivers/pci/pci-uclass.c >>>>>>>>>>>>>>>>>>>>> index 46e9c71bdf..306bea0dbf 100644 >>>>>>>>>>>>>>>>>>>>> --- a/drivers/pci/pci-uclass.c >>>>>>>>>>>>>>>>>>>>> +++ b/drivers/pci/pci-uclass.c >>>>>>>>>>>>>>>>>>>>> @@ -662,6 +662,8 @@ static int >>>>>>>>>>>>>>>>>>>>> pci_find_and_bind_driver(struct udevice *parent, >>>>>>>>>>>>>>>>>>>>> for (id = entry->match; >>>>>>>>>>>>>>>>>>>>> id->vendor || id->subvendor || >>>>>>>>>>>>>>>>>>>>> id->class_mask; >>>>>>>>>>>>>>>>>>>>> id++) { >>>>>>>>>>>>>>>>>>>>> + ofnode node; >>>>>>>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>>>>>>> if (!pci_match_one_id(id, >>>>>>>>>>>>>>>>>>>>> find_id)) >>>>>>>>>>>>>>>>>>>>> continue; >>>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>>> @@ -691,6 +693,18 @@ static int >>>>>>>>>>>>>>>>>>>>> pci_find_and_bind_driver(struct udevice *parent, >>>>>>>>>>>>>>>>>>>>> goto error; >>>>>>>>>>>>>>>>>>>>> debug("%s: Match found: %s\n", >>>>>>>>>>>>>>>>>>>>> __func__, drv->name); >>>>>>>>>>>>>>>>>>>>> dev->driver_data = >>>>>>>>>>>>>>>>>>>>> find_id->driver_data; >>>>>>>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>>>>>>> + dev_for_each_subnode(node, >>>>>>>>>>>>>>>>>>>>> parent) { >>>>>>>>>>>>>>>>>>>>> + phys_addr_t df, size; >>>>>>>>>>>>>>>>>>>>> + df = >>>>>>>>>>>>>>>>>>>>> ofnode_get_addr_size(node, "reg", &size); >>>>>>>>>>>>>>>>>>>>> + >>>>>>>>>>>>>>>>>>>>> + if (PCI_FUNC(df) == >>>>>>>>>>>>>>>>>>>>> PCI_FUNC(bdf) && >>>>>>>>>>>>>>>>>>>>> + PCI_DEV(df) == >>>>>>>>>>>>>>>>>>>>> PCI_DEV(bdf)) { >>>>>>>>>>>>>>>>>>>>> + dev->node = node; >>>>>>>>>>>>>>>>>>>>> + break; >>>>>>>>>>>>>>>>>>>>> + } >>>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>>> The function pci_find_and_bind_driver() is supposed to >>>>>>>>>>>>>>>>>>>> bind devices >>>>>>>>>>>>>>>>>>>> that are NOT in the device tree. Adding device tree access >>>>>>>>>>>>>>>>>>>> in this >>>>>>>>>>>>>>>>>>>> routine is quite odd. You can add the EHCI controller that >>>>>>>>>>>>>>>>>>>> need such >>>>>>>>>>>>>>>>>>>> PHY subnodes in the device tree and there is no need to >>>>>>>>>>>>>>>>>>>> modify >>>>>>>>>>>>>>>>>>>> anything I believe. If you are looking for an example, >>>>>>>>>>>>>>>>>>>> please check >>>>>>>>>>>>>>>>>>>> pciuart0 in arch/x86/dts/crownbay.dts. >>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>>> Well this does not work for me, the EHCI PCI doesn't get a >>>>>>>>>>>>>>>>>>> DT node >>>>>>>>>>>>>>>>>>> assigned, check r8a7794.dtsi for the PCI devices I use. >>>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I think that's because you don't specify a "compatible" >>>>>>>>>>>>>>>>>> string for >>>>>>>>>>>>>>>>>> these two EHCI PCI nodes. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> That's perfectly fine, why should I specify it ? Linux has no >>>>>>>>>>>>>>>>> problem >>>>>>>>>>>>>>>>> with it either. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> Without a "compatible" string, DM does not bind any device in >>>>>>>>>>>>>>>> the >>>>>>>>>>>>>>>> device tree to a driver, hence no device node created. This is >>>>>>>>>>>>>>>> not >>>>>>>>>>>>>>>> Linux. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> DT is NOT Linux specific, it is OS-agnostic, DT describes >>>>>>>>>>>>>>> hardware and >>>>>>>>>>>>>>> hardware only. If U-Boot cannot parse DT correctly, U-Boot is >>>>>>>>>>>>>>> broken and >>>>>>>>>>>>>>> must be fixed. >>>>>>>>>>>>>>> >>>>>>>>>>>>>>> This is a fix. If there is a better fix, I am open to it. >>>>>>>>>>>>>> >>>>>>>>>>>>>> DT should but isn't always OS agnostic. DTS files that reside >>>>>>>>>>>>>> in the >>>>>>>>>>>>>> Linux Kernel are in practice is Linux-centric with the >>>>>>>>>>>>>> expectation that >>>>>>>>>>>>>> even if you could solve a given problem with valid DTS changes >>>>>>>>>>>>>> you make >>>>>>>>>>>>>> whatever is parsing it do additional logic instead. That, >>>>>>>>>>>>>> approximately, is what your patch is doing. If you added some HW >>>>>>>>>>>>>> description information to the dtsi file everything would work as >>>>>>>>>>>>>> expected as your DTS is describing the hardware and U-Boot is >>>>>>>>>>>>>> reading >>>>>>>>>>>>>> that description and figuring out what to do with it. >>>>>>>>>>>>> >>>>>>>>>>>>> Yes, you need additional logic to match the PCI controller >>>>>>>>>>>>> subnode in DT >>>>>>>>>>>>> with PCI device BFD, that's expected. You do NOT need extra >>>>>>>>>>>>> compatibles, >>>>>>>>>>>>> the PCI bus gives you enough information to match a driver on >>>>>>>>>>>>> them. In >>>>>>>>>>>>> fact, adding a compatible can interfere with this matching. >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Please, read U-Boot's doc/driver-model/pci-info.txt. You really >>>>>>>>>>>> don't >>>>>>>>>>>> understand current implementation in U-Boot. In short, U-Boot >>>>>>>>>>>> supports >>>>>>>>>>>> two scenarios for PCI driver binding: >>>>>>>>>>> >>>>>>>>>>> That documentation is wrong and needs to be fixed. The compatible is >>>>>>>>>>> optional. >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> No it is not wrong. The documentation reflects the update-to-date >>>>>>>>>> U-Boot support of PCI bus with DM. >>>>>>>>> >>>>>>>>> Which is incomplete, as it cannot parse subnodes without compatible >>>>>>>>> strings. >>>>>>>>> >>>>>>>> >>>>>>>> No, it's by design, as I said many times. It can support parsing >>>>>>>> subnodes with a "compatible" string existence. >>>>>>> >>>>>>> It can support parsing subnodes with a "compatible" string existence AND >>>>>>> It can NOT support parsing subnodes without a "compatible" string >>>>>>> existence THUS It is incomplete. >>>>>>> >>>>>>>>>>>> - Declare a PCI device in the device tree. That requires >>>>>>>>>>>> specifying a >>>>>>>>>>>> 'compatible' string as well as 'reg' property as defined by the >>>>>>>>>>>> 'PCI >>>>>>>>>>>> Bus Binding' spec. DM uses the 'compatible' string to bind the >>>>>>>>>>>> driver >>>>>>>>>>>> for the device. >>>>>>>>>>>> - Don't declare a PCI device in the device tree. Instead, using >>>>>>>>>>>> U_BOOT_PCI_DEVICE() to declare a device and driver mapping. >>>>>>>>>>>> >>>>>>>>>>>> You can choose either two when you support PCI devices on your >>>>>>>>>>>> board, >>>>>>>>>>>> but you cannot mix both support together and make them a mess. In >>>>>>>>>>>> this >>>>>>>>>>>> patch, you hacked pci_find_and_bind_driver() which is the 2nd >>>>>>>>>>>> scenario >>>>>>>>>>>> to support the 1st scenario. >>>>>>>>>>> >>>>>>>>>>> Again, the DT contains all the required information to bind the >>>>>>>>>>> node and >>>>>>>>>>> the driver instance. Clearly, we need option 3 for this. >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Then that's a new design proposal. Anything that wants to mess up >>>>>>>>>> current design is a hack. >>>>>>>>> >>>>>>>>> That means every single patch anyone submits is now a hack ? Please >>>>>>>>> ... >>>>>>>>> >>>>>>>> >>>>>>>> I never said "every single patch anyone submits is now a hack". "You >>>>>>>> are inserting words into my mouth and I dislike that." I said your >>>>>>>> current patch is against the design, and mess up current design which >>>>>>>> is a hack. >>>>>>> >>>>>>> But then every patch which changes the behavior is against "the design" >>>>>>> and thus is a hack. Ultimately, most improvements would be considered a >>>>>>> hack. >>>>>> >>>>>> No it depends. For this case, there are two options that DM PCI >>>>>> currently provides. You created a 3rd option that bring option 1 and 2 >>>>>> together in a mixed way, yet without any documenting and additional >>>>>> other changes. If you posted such changes in a series and have all >>>>>> stuff well considered, I would not consider it a hack, but a proposed >>>>>> design change. >>>>> >>>>> Also, the design document is not immutable and can and should be updated >>>>> as needed to match changes in the code. >>>> >>>> So what is the conclusion here ? Patch the design document and apply >>>> this patch as is ? >>>> >>> >>> I think we should see Simon's comments before we move forward. The >>> proposal I made before should come in a series, not just >>> documentation. >> >> Your proposal mostly covers sandbox and that can be done separately. >> My proposal is to update documentation and fix the code. > > There are more changes than the sandbox. Given the participants in > this thread, I suspect nobody else would care the design if you had > only changed whatever you like in a patch or two. Then we will end up > leaving such incomplete design in the source tree and confusing people > maybe for years until someone tries to fix up the things all together.
How is that incomplete and confusing , can you elaborate ? > I hope we can do things right from start. From start ... how ? -- Best regards, Marek Vasut _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot