| Message ID | 49da5d0cf961fef23a1622253825443eb51d660d.1738963156.git.andrea.porta@suse.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add support for RaspberryPi RP1 PCI device using a DT overlay | expand |
Hi Andrea, Am 07.02.25 um 22:31 schrieb Andrea della Porta: > The RP1 driver uses the infrastructure enabled by OF_OVERLAY config > option. Enable that option in defconfig in order to produce a kernel > usable on RaspberryPi5 avoiding to enable it separately. > > Signed-off-by: Andrea della Porta <andrea.porta@suse.com> > --- > This patch is *OPTIONAL* since I'm not sure if OF_OVERLAY is a desirable > feature to have enabled by default. It would be advisable to have it included > so that 'make defconfig' can produce a kernel config that will work out > of the box on Rpi5, otherwise OF_OVERLAY has to be enabled separately. I think this isn't a good approach to convince the arm64 maintainer. This change is not really optional for the Raspberry Pi 5 and possible users/testers/CI rely on a working default configuration. So my first suggestion would be to provide a scripts/bloat-o-meter output (before/after). Based on this the maintainer can better decided. In case this change is still rejected, we still have the option of something like this [1] Best regards [1] - https://patchwork.kernel.org/project/linux-kbuild/patch/20200203184820.4433-3-nsaenzjulienne@suse.de/
Hi Stefan, On 14:42 Sat 08 Feb , Stefan Wahren wrote: > Hi Andrea, > > Am 07.02.25 um 22:31 schrieb Andrea della Porta: > > The RP1 driver uses the infrastructure enabled by OF_OVERLAY config > > option. Enable that option in defconfig in order to produce a kernel > > usable on RaspberryPi5 avoiding to enable it separately. > > > > Signed-off-by: Andrea della Porta <andrea.porta@suse.com> > > --- > > This patch is *OPTIONAL* since I'm not sure if OF_OVERLAY is a desirable > > feature to have enabled by default. It would be advisable to have it included > > so that 'make defconfig' can produce a kernel config that will work out > > of the box on Rpi5, otherwise OF_OVERLAY has to be enabled separately. > I think this isn't a good approach to convince the arm64 maintainer. > This change is not really optional for the Raspberry Pi 5 and possible > users/testers/CI rely on a working default configuration. > > So my first suggestion would be to provide a scripts/bloat-o-meter > output (before/after). Based on this the maintainer can better decided. I agree with you. IIUC what you are proposing, the following metrics should help to decide. The defconfig kernel with CONFIG_OF_OVERLAY=y added (wrt to the defconfig one without that set) has: - same uncompressed kernel image size (due to ELF section alignment I guess) - ~7Kb bigger Image.gz - 3 new modules (all related to RP1, i.e.: clk-rp1, pinctrl-rp1 and rp1-pci) - 27 added symbols, of which 5 exported hoping this is enough to gather a rough idea of the impact. > > In case this change is still rejected, we still have the option of > something like this [1] I'm ready to go down this way should the previous numbers not be convincing enough. Many thanks, Andrea > > Best regards > > [1] - > https://patchwork.kernel.org/project/linux-kbuild/patch/20200203184820.4433-3-nsaenzjulienne@suse.de/
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig index cc70793e97ef..ca492fbd2773 100644 --- a/arch/arm64/configs/defconfig +++ b/arch/arm64/configs/defconfig @@ -1643,6 +1643,7 @@ CONFIG_FPGA_BRIDGE=m CONFIG_ALTERA_FREEZE_BRIDGE=m CONFIG_FPGA_REGION=m CONFIG_OF_FPGA_REGION=m +CONFIG_OF_OVERLAY=y CONFIG_TEE=y CONFIG_OPTEE=y CONFIG_MUX_GPIO=m
The RP1 driver uses the infrastructure enabled by OF_OVERLAY config option. Enable that option in defconfig in order to produce a kernel usable on RaspberryPi5 avoiding to enable it separately. Signed-off-by: Andrea della Porta <andrea.porta@suse.com> --- This patch is *OPTIONAL* since I'm not sure if OF_OVERLAY is a desirable feature to have enabled by default. It would be advisable to have it included so that 'make defconfig' can produce a kernel config that will work out of the box on Rpi5, otherwise OF_OVERLAY has to be enabled separately. arch/arm64/configs/defconfig | 1 + 1 file changed, 1 insertion(+)