On Tue, Jul 7, 2020 at 11:01 PM Bjørn Mork <bjorn@xxxxxxx> wrote: > > [ previously posted to kernelnewbies ] > > I have "always" tested simple patches by rebuilding just the affected > driver on whatever kernel I happen to run. Like this: > > bjorn@miraculix:/usr/local/src/git/linux$ make -C /lib/modules/4.19.0-9-amd64/build M=$(pwd)/drivers/net/usb clean > make: Entering directory '/usr/src/linux-headers-4.19.0-9-amd64' > CLEAN /usr/local/src/git/linux/drivers/net/usb/Module.symvers > make: Leaving directory '/usr/src/linux-headers-4.19.0-9-amd64' > bjorn@miraculix:/usr/local/src/git/linux$ make -C /lib/modules/4.19.0-9-amd64/build M=$(pwd)/drivers/net/usb qmi_wwan.ko > make: Entering directory '/usr/src/linux-headers-4.19.0-9-amd64' > CC [M] /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.o > MODPOST 1 modules > CC /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.mod.o > LD [M] /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.ko > make: Leaving directory '/usr/src/linux-headers-4.19.0-9-amd64' > > > But this is broken for some reason with recent Debian (bullseye/sid) > kernels, based on 5.6 or 5.7 kernels. They will always compile all > source files in the directory, even of most of them are not necessary > for the requested target: > > > bjorn@miraculix:/usr/local/src/git/linux$ make -C /lib/modules/5.7.0-1-amd64/build M=$(pwd)/drivers/net/usb clean > make: Entering directory '/usr/src/linux-headers-5.7.0-1-amd64' > CLEAN /usr/local/src/git/linux/drivers/net/usb/Module.symvers > make: Leaving directory '/usr/src/linux-headers-5.7.0-1-amd64' > bjorn@miraculix:/usr/local/src/git/linux$ make -C /lib/modules/5.7.0-1-amd64/build M=$(pwd)/drivers/net/usb qmi_wwan.ko > make: Entering directory '/usr/src/linux-headers-5.7.0-1-amd64' > AR /usr/local/src/git/linux/drivers/net/usb/built-in.a > CC [M] /usr/local/src/git/linux/drivers/net/usb/catc.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/kaweth.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/pegasus.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/rtl8150.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/r8152.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/hso.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/lan78xx.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/asix_devices.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/asix_common.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/ax88172a.o > LD [M] /usr/local/src/git/linux/drivers/net/usb/asix.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/ax88179_178a.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc_ether.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc_eem.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/dm9601.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/sr9700.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/sr9800.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/smsc75xx.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/smsc95xx.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/gl620a.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/net1080.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/plusb.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/rndis_host.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc_subset.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/zaurus.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/mcs7830.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/usbnet.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/int51x1.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc-phonet.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/kalmia.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/ipheth.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/sierra_net.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cx82310_eth.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc_ncm.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/huawei_cdc_ncm.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/lg-vl600.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/cdc_mbim.o > CC [M] /usr/local/src/git/linux/drivers/net/usb/ch9200.o > MODPOST 1 modules > CC [M] /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.mod.o > LD [M] /usr/local/src/git/linux/drivers/net/usb/qmi_wwan.ko > make: Leaving directory '/usr/src/linux-headers-5.7.0-1-amd64' > > > > > Why is this? Am I doing something wrong here? Thanks for the report. You are not doing anything wrong. This is a regression of f566e1fbadb6 Please check this: https://patchwork.kernel.org/patch/11649263/ It will be included in the next pull request, and eventually back-ported to stable kernels. Meanwhile, if M= build is not important, you can compile-test a particular module with in-tree build: $ make drivers/net/usb/qmi_wwan.ko -- Best Regards Masahiro Yamada
