Hi everyone, Firstly, apologies to anyone on the long cc list that turns out not to be particularly interested in the following, but you were all marked as cc'd in the commit message below.
I've found a problem that isn't present in 5.2 series or 4.19 series kernels, and seems to have arrived in 5.3-rc1. The problem is that if I suspend (to ram) my laptop, on resume 14 minutes or more after suspending, I have no networking functionality. If I resume the laptop after 13 minutes or less, networking works fine. I haven't tried to get finer grained timings between 13 and 14 minutes, but can do if it would help. ifconfig shows that wlan0 is still up and still has its assigned ip address but, for instance, a ping of any other device on my network, fails as does pinging, say, kernel.org. I've tried "downing" the network with (/sbin/ifdown) and unloading the iwlmvm module and then reloading the module and "upping" (/sbin/ifup) the network, but my network is still unusable. I should add that the problem also manifests if I hibernate the laptop, although my testing of this has been minimal. I can do more if required. As I say, the problem first appears in 5.3-rc1, so I've bisected between 5.2.0 and 5.3-rc1 and that concluded with: [chris:~/kernel/linux]$ git bisect good 7ac8707479886c75f353bfb6a8273f423cfccb23 is the first bad commit commit 7ac8707479886c75f353bfb6a8273f423cfccb23 Author: Vincenzo Frascino <[email protected]> Date: Fri Jun 21 10:52:49 2019 +0100 x86/vdso: Switch to generic vDSO implementation The x86 vDSO library requires some adaptations to take advantage of the newly introduced generic vDSO library. Introduce the following changes: - Modification of vdso.c to be compliant with the common vdso datapage - Use of lib/vdso for gettimeofday [ tglx: Massaged changelog and cleaned up the function signature formatting ] Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Catalin Marinas <[email protected]> Cc: Will Deacon <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Russell King <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: Paul Burton <[email protected]> Cc: Daniel Lezcano <[email protected]> Cc: Mark Salyzyn <[email protected]> Cc: Peter Collingbourne <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Dmitry Safonov <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Huw Davies <[email protected]> Cc: Shijith Thotton <[email protected]> Cc: Andre Przywara <[email protected]> Link: https://lkml.kernel.org/r/[email protected] arch/x86/Kconfig | 3 + arch/x86/entry/vdso/Makefile | 9 ++ arch/x86/entry/vdso/vclock_gettime.c | 245 ++++--------------------------- arch/x86/entry/vdso/vdsox32.lds.S | 1 + arch/x86/entry/vsyscall/Makefile | 2 - arch/x86/entry/vsyscall/vsyscall_gtod.c | 83 ----------- arch/x86/include/asm/pvclock.h | 2 +- arch/x86/include/asm/vdso/gettimeofday.h | 191 ++++++++++++++++++++++++ arch/x86/include/asm/vdso/vsyscall.h | 44 ++++++ arch/x86/include/asm/vgtod.h | 75 +--------- arch/x86/include/asm/vvar.h | 7 +- arch/x86/kernel/pvclock.c | 1 + 12 files changed, 284 insertions(+), 379 deletions(-) delete mode 100644 arch/x86/entry/vsyscall/vsyscall_gtod.c create mode 100644 arch/x86/include/asm/vdso/gettimeofday.h create mode 100644 arch/x86/include/asm/vdso/vsyscall.h To confirm my bisection was correct, I did a git checkout of 7ac8707479886c75f353bfb6a8273f423cfccb2. As expected, the kernel exhibited the problem I've described. However, a kernel built at the immediately preceding (parent?) commit (bfe801ebe84f42b4666d3f0adde90f504d56e35b) has a working network after a (>= 14minute) suspend/resume cycle. As the module name implies, I'm using wireless networking. The hardware is detected as "Intel(R) Wireless-AC 9260 160MHz, REV=0x324" by iwlwifi. I'm more than happy to provide additional diagnostics (but may need a little hand-holding) and to apply diagnostic or fix patches, but please cc me on any reply as I'm not subscribed to any of the kernel-related mailing lists. Chris
