diff options
Diffstat (limited to 'target/linux/mvebu/patches-3.18/030-do_not_register_custom_DMA_operations_when_coherency_is_disabled.patch')
-rw-r--r-- | target/linux/mvebu/patches-3.18/030-do_not_register_custom_DMA_operations_when_coherency_is_disabled.patch | 48 |
1 files changed, 0 insertions, 48 deletions
diff --git a/target/linux/mvebu/patches-3.18/030-do_not_register_custom_DMA_operations_when_coherency_is_disabled.patch b/target/linux/mvebu/patches-3.18/030-do_not_register_custom_DMA_operations_when_coherency_is_disabled.patch deleted file mode 100644 index 28cfc9d..0000000 --- a/target/linux/mvebu/patches-3.18/030-do_not_register_custom_DMA_operations_when_coherency_is_disabled.patch +++ /dev/null @@ -1,48 +0,0 @@ -This patch is a partial backport of commit ef01c6c36bb8 ("ARM: mvebu: -remove Armada 375 Z1 workaround for I/O coherency"). This commit was -merged in v3.19, so kernel versions later than v3.19 are not affected -by the problem that this commit fixes. - -It does not make a lot of sense to backport this commit entirely, -since it is mainly removing some no longer useful code. However, this -commit is also making sure that the bus_register_notifier that -register the custom DMA operations that should be used for HW I/O -coherency does not get registered when said HW I/O coherency is not -enabled. - -This is particularly critical since we have decided to disable HW I/O -coherency completely in all kernels < 4.0, to be on the safe side, -while experimenting a new implementation of the HW I/O coherency in >= -4.0. - -Without this commit, kernels earlier than 3.18 have the custom DMA -operations normally used for HW I/O coherency registered (they don't -do cache maintenance operations), while HW I/O coherency is -disabled. It essentially causes every DMA transfer to transfer -garbage. - -The issue fixed by this commit was introduced by 5ab5afd8ba83 ("ARM: -mvebu: implement Armada 375 coherency workaround"), but it was not -visible until now since it didn't cause any problem when HW I/O -coherency is enabled. - -Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> -Cc: <stable@vger.kernel.org> v3.16..v3.18 ---- - arch/arm/mach-mvebu/coherency.c | 5 +++-- - 1 file changed, 3 insertions(+), 2 deletions(-) - ---- a/arch/arm/mach-mvebu/coherency.c -+++ b/arch/arm/mach-mvebu/coherency.c -@@ -391,8 +391,9 @@ static int __init coherency_late_init(vo - armada_375_coherency_init_wa(); - } - -- bus_register_notifier(&platform_bus_type, -- &mvebu_hwcc_nb); -+ if (coherency_available()) -+ bus_register_notifier(&platform_bus_type, -+ &mvebu_hwcc_nb); - - return 0; - } |