Messages in this thread | | | Subject | Re: [PATCH] alpha: io: reorder barriers to guarantee writeX() and iowriteX() ordering #2 | From | Sinan Kaya <> | Date | Tue, 17 Apr 2018 14:43:01 -0400 |
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On 4/16/2018 6:16 PM, Sinan Kaya wrote: > memory-barriers.txt has been updated with the following requirement. > > "When using writel(), a prior wmb() is not needed to guarantee that the > cache coherent memory writes have completed before writing to the MMIO > region." > > Current writeX() and iowriteX() implementations on alpha are not > satisfying this requirement as the barrier is after the register write. > > Move mb() in writeX() and iowriteX() functions to guarantee that HW > observes memory changes before performing register operations. > > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> > Reported-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/alpha/kernel/io.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-)
Sorry for catching this late but this also needs to go to 4.17 after review.
I missed the writel() implementation on arch/alpha/kernel/io.c file on my first patch.
-- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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