| Message ID | 20230126135049.708524-1-rick.wertenbroek@gmail.com |
|---|---|
| Headers | show |
| Series | PCI: rockchip: Fix PCIe endpoint controller driver | expand |
Hi Rick, Thanks very much for your work. On Thu, Jan 26, 2023 at 02:50:40PM +0100, Rick Wertenbroek wrote: > This is a series of patches that fixes the PCIe endpoint controller driver > for the Rockchip RK3399 SoC. It is based on Linux kernel 6.0.19 > > The original driver in mainline had issues and would not allow for the > RK3399 to operate in PCIe endpoint mode. This patch series fixes that so > that the PCIe core controller of the RK3399 SoC can now act as a PCIe > endpoint. So we merged cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller") when it actually didn't work? Ouch. Thanks for fixing it and testing it. > Rick Wertenbroek (8): > PCI: rockchip: Removed writes to unused registers > PCI: rockchip: Fixed setup of Device ID > PCI: rockchip: Fixed endpoint controller Configuration Request Retry > Status > PCI: rockchip: Added poll and timeout to wait for PHY PLLs to be > locked > PCI: rockchip: Added dtsi entry for PCIe endpoint controller > PCI: rockchip: Fixed window mapping and address translation for > endpoint > PCI: rockchip: Fixed legacy IRQ generation for endpoint > PCI: rockchip: Fixed MSI generation from PCIe endpoint core For the next iteration, can you please update these subject lines and commit logs to: - Use imperative mood, i.e., read like a command, instead of a past tense description of what was done. For example, say "Remove writes to unused registers" instead of "Removed writes ..." - Be more specific when possible. "Fix" conveys no information about the actual code change. For example, "Fixed endpoint controller Configuration Request Retry Status" gives a general idea, but it would be more useful if it said something about clearing config mode after probe. - Say what the patch does in the commit log. The current ones often describe a *problem*, but do not explicitly say what the patch does. The commit log should be complete in itself even without the subject line, so it usually contains a slightly expanded version of the subject line. - Split patches that do more than one logical thing. The commit log for "Fixed MSI generation ..." talks about a u16/u32 shift issue, but the patch also adds an unrelated check for multi-function devices. - If a patch is a fix for an existing issue and may need to be backported, identify the commit that introduced the issue and add "Fixes: " lines. This helps distros figure out whether and how far to backport patches. - Refer to the device consistently. I see: RK3399 PCI EP core RK3399 SoC PCIe EP core RK3399 PCIe endpoint core I vote for "RK3399 PCIe Endpoint core". Notes about imperative mood: https://chris.beams.io/posts/git-commit/ https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v6.0#n94 > arch/arm64/boot/dts/rockchip/rk3399.dtsi | 25 ++++ > drivers/pci/controller/pcie-rockchip-ep.c | 149 +++++++++++----------- > drivers/pci/controller/pcie-rockchip.c | 16 +++ > drivers/pci/controller/pcie-rockchip.h | 36 ++++-- > 4 files changed, 137 insertions(+), 89 deletions(-) > > -- > 2.25.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Hello, Bjorn Thank you for your prompt reply and helpful comments. Le jeu. 26 janv. 2023 à 15:52, Bjorn Helgaas <helgaas@kernel.org> a écrit : > > Hi Rick, > > Thanks very much for your work. > > On Thu, Jan 26, 2023 at 02:50:40PM +0100, Rick Wertenbroek wrote: > > This is a series of patches that fixes the PCIe endpoint controller driver > > for the Rockchip RK3399 SoC. It is based on Linux kernel 6.0.19 > > > > The original driver in mainline had issues and would not allow for the > > RK3399 to operate in PCIe endpoint mode. This patch series fixes that so > > that the PCIe core controller of the RK3399 SoC can now act as a PCIe > > endpoint. > > So we merged cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip > PCIe controller") when it actually didn't work? Ouch. Thanks for > fixing it and testing it. It seems it wasn't fully tested, the code compiles and kernel module loads, but further functionality didn't seem to have been tested (e.g., lspci, and with the pcitest tool and pci_endpoit_test_driver). > > For the next iteration, can you please update these subject lines and > commit logs to: Thank you, I will prepare the changes and add them to the next iteration with changes from other comments that may arise. > > - Use imperative mood, i.e., read like a command, instead of a past > tense description of what was done. For example, say "Remove > writes to unused registers" instead of "Removed writes ..." > > - Be more specific when possible. "Fix" conveys no information > about the actual code change. For example, "Fixed endpoint > controller Configuration Request Retry Status" gives a general > idea, but it would be more useful if it said something about > clearing config mode after probe. > > - Say what the patch does in the commit log. The current ones often > describe a *problem*, but do not explicitly say what the patch > does. The commit log should be complete in itself even without > the subject line, so it usually contains a slightly expanded > version of the subject line. > > - Split patches that do more than one logical thing. The commit log > for "Fixed MSI generation ..." talks about a u16/u32 shift issue, > but the patch also adds an unrelated check for multi-function > devices. I will. I tried to split everything into the function it was related to, but I now understand I should split even more so that the commit message and changes are more tightly linked. > > - If a patch is a fix for an existing issue and may need to be > backported, identify the commit that introduced the issue and add > "Fixes: " lines. This helps distros figure out whether and how > far to backport patches. Does this mean I should refer to the commit cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip PCIe controller") ? Because it wasn't working in the first place ? > > - Refer to the device consistently. I see: > RK3399 PCI EP core > RK3399 SoC PCIe EP core > RK3399 PCIe endpoint core > I vote for "RK3399 PCIe Endpoint core". I agree. > > Notes about imperative mood: > https://chris.beams.io/posts/git-commit/ > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v6.0#n94 Thank you for all the pointers, I'll take them into account for the next iteration. This is the first time I actually submitted a series of patches to the LKML so it's all relatively new to me.
On Thu, Jan 26, 2023 at 04:23:57PM +0100, Rick Wertenbroek wrote: > Le jeu. 26 janv. 2023 à 15:52, Bjorn Helgaas <helgaas@kernel.org> a écrit : > > Thanks very much for your work. > > > > On Thu, Jan 26, 2023 at 02:50:40PM +0100, Rick Wertenbroek wrote: > > > This is a series of patches that fixes the PCIe endpoint controller driver > > > for the Rockchip RK3399 SoC. It is based on Linux kernel 6.0.19 > > > > > > The original driver in mainline had issues and would not allow for the > > > RK3399 to operate in PCIe endpoint mode. This patch series fixes that so > > > that the PCIe core controller of the RK3399 SoC can now act as a PCIe > > > endpoint. > > > > So we merged cf590b078391 ("PCI: rockchip: Add EP driver for Rockchip > > PCIe controller") when it actually didn't work? Ouch. Thanks for > > fixing it and testing it. > > It seems it wasn't fully tested, the code compiles and kernel module loads, > but further functionality didn't seem to have been tested > (e.g., lspci, and with the pcitest tool and pci_endpoit_test_driver). OK, I guess that happens sometimes. Glad you're getting it into shape! > Does this mean I should refer to the commit cf590b078391 > ("PCI: rockchip: Add EP driver for Rockchip PCIe controller") ? > Because it wasn't working in the first place ? Yes, I think so. > Thank you for all the pointers, I'll take them into account for the > next iteration. This is the first time I actually submitted a series of > patches to the LKML so it's all relatively new to me. Welcome to Linux, and great start! Bjorn
This is a series of patches that fixes the PCIe endpoint controller driver for the Rockchip RK3399 SoC. It is based on Linux kernel 6.0.19 The original driver in mainline had issues and would not allow for the RK3399 to operate in PCIe endpoint mode. This patch series fixes that so that the PCIe core controller of the RK3399 SoC can now act as a PCIe endpoint. This patch series has been tested on kernel 6.0.19 (and 5.19) on real hardware, a FriendlyElec NanoPC-T4 RK3399 based single computer board connected to a host computer through PCIe x1 and x4. The PCIe endpoint test function driver was loaded on the SoC and the PCIe endpoint test driver was loaded on the host computer. The following tests were executed through this setup : * enumeration of the PCIe endpoint device (lspci) lspci -vvv * validation of PCI header and capabilities setpci and lspci -xxxx * device was recognized by host computer dans PCIe endpoint test driver was loaded lspci -v states "Kernel modules: pci_endpoint_test" * tested the BARs 0-5 sudo /sur/bin/pcitest -b 0 ... sudo /usr/bin/pcitest -b 5 * tested legacy interrupt through the test driver sudo /usr/bin/pcitest -i 0 sudo /usr/bin/pcitest -l * tested MSI interrupt through the test driver sudo /usr/bin/pcitest -i 1 sudo /usr/bin/pcitest -m 1 * tested read/write to and from host through the test driver with checksum sudo /usr/bin/pcitest -r -s 1024 sudo /usr/bin/pcitest -w -s 1024 * tested read/write with DMA enabled (all read/write tests also did IRQ) sudo /usr/bin/pcitest -r -d -s 8192 sudo /usr/bin/pcitest -w -d -s 8192 Summary of changes : This patch series is composed of 8 patches that do the following : * Removed writes to unused registers in the PCIe core register space. The registers that were written to is marked "unused" and read only in the technical reference manual of the RK3399 SoC. * Fixed setup to the PCI Device ID (DID), this was written to a read only register and therefore would not update the DID. * Fixed setup of the PCIe endpoint controller so that it would stop sending Configuration Request Retry Status (CRS) messages to the host once configured, without this the host would retry until timeout and cancel the PCI configuration. * Added a poll with timeout to check the PHY PLL lock status, this is the only patch that also applies to the root complex function of the PCIe core controller, without this the kernel would sometimes access registers in the PHY PLL clock domain when the PLLs were not yet locked and the system would hang. This was hackily solved in other non mainline patches (e.g., in armbian) with a "msleep()" that was added after PHY PLL configuration but without realizing why it was needed. A poll with timeout seems like a sane approach. * Added a dtsi entry for the PCIe endpoint controller. The new entry is in "disabled" status by default, so unless it is explicitly enabled it will not conflict with the PCIe root complex controller entry. Developers that will enable it would know that the root complex function then must be disabled, this can be done in the board level DTS. * Fixed the window translation between CPU space and PCI space. Allows up to 32 memory windows, with (1MB) page allocation and mapping. * Fixed the legacy IRQ (INTx) generation of the PCIe core in endpoint mode. * Fixed the generation of message signalled interrupts (MSI) of the PCIe core in endpoint mode. Thank you in advance for reviewing these changes and hopefully getting this merged. Having a functional PCIe endpoint controller driver for the RK3399 would allow to develop further PCIe endpoint functions through the Linux PCIe endpoint framework using this SoC. I have tested and confirmed all basic functionality required for the endpoint with the test driver and tools. With the previous state of the driver the device would not even be enumerated by the host computer (mainly because of CRS messages being sent back to the root complex) and tests would not pass (driver would not even be loaded because DID was not set correctly) and then only the BAR test would pass. Now all tests pass as stated above. Best regards Rick Commands used on the SoC to launch the endpoint function (configfs) : modprobe -i pci-epf-test mkdir -p /sys/kernel/config/pci_ep/functions/pci_epf_test/pci_epf_test.0 echo 0xb500 > /sys/kernel/config/pci_ep/functions/pci_epf_test/pci_epf_test.0/deviceid echo 0x104c > /sys/kernel/config/pci_ep/functions/pci_epf_test/pci_epf_test.0/vendorid echo 16 > /sys/kernel/config/pci_ep/functions/pci_epf_test/pci_epf_test.0/msi_interrupts ln -s /sys/kernel/config/pci_ep/functions/pci_epf_test/pci_epf_test.0 \ /sys/kernel/config/pci_ep/controllers/fd000000.pcie-ep/ echo 1 > /sys/kernel/config/pci_ep/controllers/fd000000.pcie-ep/start Note: to enable the endpoint controller on the board the file : arch/arm64/boot/dts/rockchip/rk3399-nanopc-t4.dts Was edited to set the status of &pcie0 to "disabled" and &pcie0_ep to "okay". This is not submitted as a patch because most users will use the PCIe core controller in host (root complex) mode rather than endpoint mode. Rick Wertenbroek (8): PCI: rockchip: Removed writes to unused registers PCI: rockchip: Fixed setup of Device ID PCI: rockchip: Fixed endpoint controller Configuration Request Retry Status PCI: rockchip: Added poll and timeout to wait for PHY PLLs to be locked PCI: rockchip: Added dtsi entry for PCIe endpoint controller PCI: rockchip: Fixed window mapping and address translation for endpoint PCI: rockchip: Fixed legacy IRQ generation for endpoint PCI: rockchip: Fixed MSI generation from PCIe endpoint core arch/arm64/boot/dts/rockchip/rk3399.dtsi | 25 ++++ drivers/pci/controller/pcie-rockchip-ep.c | 149 +++++++++++----------- drivers/pci/controller/pcie-rockchip.c | 16 +++ drivers/pci/controller/pcie-rockchip.h | 36 ++++-- 4 files changed, 137 insertions(+), 89 deletions(-)