On Fri, Apr 20, 2018 at 9:20 AM, Sinan Kaya <okaya@xxxxxxxxxxxxxx> wrote: > 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 <okaya@xxxxxxxxxxxxxx> >>> Reported-by: Arnd Bergmann <arnd@xxxxxxxx> >>> --- >>> 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. Yes, I will pick it up for 4.17. Thanks for the patch. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
