Hi Matt, On 4/17/2018 2:43 PM, Sinan Kaya wrote: > 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 <[email protected]> >> Reported-by: Arnd Bergmann <[email protected]> >> --- >> 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. >
Can you also queue this for 4.17? There are already drivers checked into 4.17 that dropped the unnecessary barriers. I really hate to see Alpha broken because of this. Sinan -- 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.
