[ Back-porting v4.2 patches to v4.1 LTS ] On 26/11/2015 09:54, Mason wrote: > Over the past few months, I wrote board-support code based on kernel v4.2 > and things worked as expected. > > Then I had to rebase to a LTS kernel (I used v4.1.13) and something broke > in the L2 cache setup. Apparently, Russell King did a lot of fixing and > cleaning up between v4.1 and v4.2 > > I cherry-picked the following 5 patches, and my 4.1 kernel works again: > > 346248a2d1e3a815297125c1347d90dafcc51990 ARM: l2c: avoid passing auxiliary control register through enable method > arch/arm/mm/cache-l2x0.c | 32 +++++++++++++++++--------------- > 1 file changed, 17 insertions(+), 15 deletions(-) > dc63c0733050996143a82f2b095fc378a04274f0 ARM: l2c: only unlock caches if NS_LOCKDOWN bit is set > arch/arm/mm/cache-l2x0.c | 26 +++++++++++++++++++++++++- > 1 file changed, 25 insertions(+), 1 deletion(-) > 7787be2a74dc618bf32348a0f588eebf7ebe0a06 ARM: l2c: clean up l2c_configure() > arch/arm/mm/cache-l2x0.c | 23 ++++++++++++++--------- > 1 file changed, 14 insertions(+), 9 deletions(-) > 8f80afa16002e9b4784dc1d51c48f95f52838cfb ARM: l2c: write auxiliary control register first > arch/arm/mm/cache-l2x0.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > 9749167eec6a057122b7a1ab2193abd079645aba ARM: l2c: restore the behaviour documented above l2c_enable() > arch/arm/mm/cache-l2x0.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > > The problem is that my system runs Linux in NS (non-secure) mode, and there > are a bunch of instructions that Linux can't use in that mode. > > I suspect the crash comes from trying to unconditionally unlock the caches, > thus patch dc63c0733050. > > But 9749167eec6a and 8f80afa16002 also look like good candidates for > back-porting to v4.1 > > What do you think? Any opinion on this topic? Regards. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html