| Message ID | 20250305-dra-v1-0-8dc6d9a0e1c0@nxp.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | PCI: dra7xx: Try to clean up dra7xx_pcie_cpu_addr_fixup() | expand |
On Wed, Mar 05, 2025 at 11:20:21AM -0500, Frank Li wrote: > This patches basic on > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ > > I have not hardware to test. > > Look for driver owner, who help test this and start move forward to remove > cpu_addr_fixup() work. > If you remove cpu_addr_fixup() callback, it will break backwards compatibility with old DTs. You should fix the existing DTs and continue carrying the callback for a while. - Mani
On Thu, Mar 13, 2025 at 11:35:21AM +0530, Manivannan Sadhasivam wrote: > On Wed, Mar 05, 2025 at 11:20:21AM -0500, Frank Li wrote: > > This patches basic on > > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ > > > > I have not hardware to test. > > > > Look for driver owner, who help test this and start move forward to remove > > cpu_addr_fixup() work. > > If you remove cpu_addr_fixup() callback, it will break backwards > compatibility with old DTs. Do you have any pointers to DTs that will be broken? Or to commits where they were fixed? > You should fix the existing DTs and continue carrying the callback > for a while. Any insight into where these existing DTs are used and how long they're likely to live? Bjorn
On Mon, Mar 17, 2025 at 12:30:08PM -0500, Bjorn Helgaas wrote: > On Thu, Mar 13, 2025 at 11:35:21AM +0530, Manivannan Sadhasivam wrote: > > On Wed, Mar 05, 2025 at 11:20:21AM -0500, Frank Li wrote: > > > This patches basic on > > > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ > > > > > > I have not hardware to test. > > > > > > Look for driver owner, who help test this and start move forward to remove > > > cpu_addr_fixup() work. > > > > If you remove cpu_addr_fixup() callback, it will break backwards > > compatibility with old DTs. > > Do you have any pointers to DTs that will be broken? Or to commits > where they were fixed? > Any patch that fixes issues in DT and then makes the required changes in the driver without accounting for the old DTs will break backwards compatibility. > > You should fix the existing DTs and continue carrying the callback > > for a while. > > Any insight into where these existing DTs are used and how long > they're likely to live? > There is no fixed rule in this afaik. Just like we continue to support old hardwares, we need to continue supporting old DTs for some time. The best we can do is provide some warning so that users can update their DTBs. Then we can get rid of the old DT support in the driver after some time. That's why I asked Frank to add the warning previously. - Mani
On Tue, Mar 18, 2025 at 12:14:27AM +0530, Manivannan Sadhasivam wrote: > On Mon, Mar 17, 2025 at 12:30:08PM -0500, Bjorn Helgaas wrote: > > On Thu, Mar 13, 2025 at 11:35:21AM +0530, Manivannan Sadhasivam wrote: > > > On Wed, Mar 05, 2025 at 11:20:21AM -0500, Frank Li wrote: > > > > This patches basic on > > > > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ > > > > > > > > I have not hardware to test. > > > > > > > > Look for driver owner, who help test this and start move > > > > forward to remove cpu_addr_fixup() work. > > > > > > If you remove cpu_addr_fixup() callback, it will break backwards > > > compatibility with old DTs. > > > > Do you have any pointers to DTs that will be broken? Or to > > commits where they were fixed? > > Any patch that fixes issues in DT and then makes the required > changes in the driver without accounting for the old DTs will break > backwards compatibility. Right, I guess the rule is that if we have patches that fix DT issues, we should apply them as soon as possible. And later if we ever have confidence that unfixed DTs no longer exist (or if we can identify and work around them in the kernel), we can remove the .cpu_addr_fixup(). Bjorn
On Mon, Mar 17, 2025 at 02:45:39PM -0500, Bjorn Helgaas wrote: > On Tue, Mar 18, 2025 at 12:14:27AM +0530, Manivannan Sadhasivam wrote: > > On Mon, Mar 17, 2025 at 12:30:08PM -0500, Bjorn Helgaas wrote: > > > On Thu, Mar 13, 2025 at 11:35:21AM +0530, Manivannan Sadhasivam wrote: > > > > On Wed, Mar 05, 2025 at 11:20:21AM -0500, Frank Li wrote: > > > > > This patches basic on > > > > > https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ > > > > > > > > > > I have not hardware to test. > > > > > > > > > > Look for driver owner, who help test this and start move > > > > > forward to remove cpu_addr_fixup() work. > > > > > > > > If you remove cpu_addr_fixup() callback, it will break backwards > > > > compatibility with old DTs. > > > > > > Do you have any pointers to DTs that will be broken? Or to > > > commits where they were fixed? > > > > Any patch that fixes issues in DT and then makes the required > > changes in the driver without accounting for the old DTs will break > > backwards compatibility. > > Right, I guess the rule is that if we have patches that fix DT issues, > we should apply them as soon as possible. > Right, and those patches should not break old DTs. > And later if we ever have confidence that unfixed DTs no longer exist > (or if we can identify and work around them in the kernel), we can > remove the .cpu_addr_fixup(). > Yeah. Unfortunately, we do not have a fixed deadline or process. Just like supporting the legacy broken hw, we have to keep supporting the old DTs for some time and then get rid of them. - Mani
This patches basic on https://lore.kernel.org/imx/20250128-pci_fixup_addr-v9-0-3c4bb506f665@nxp.com/ I have not hardware to test. Look for driver owner, who help test this and start move forward to remove cpu_addr_fixup() work. Signed-off-by: Frank Li <Frank.Li@nxp.com> --- Frank Li (2): ARM: dts: ti: dra7: Correct ranges for PCIe and parent bus nodes PCI: dra7xx: Use use_parent_dt_ranges and clean up dra7xx_pcie_cpu_addr_fixup() arch/arm/boot/dts/ti/omap/dra7.dtsi | 18 +++++++++--------- drivers/pci/controller/dwc/pci-dra7xx.c | 8 +------- 2 files changed, 10 insertions(+), 16 deletions(-) --- base-commit: 1552be4855dacca5ea39b15b1ef0b96c91dbea0d change-id: 20250305-dra-a7fea1c035bd Best regards, --- Frank Li <Frank.Li@nxp.com>