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    SubjectRe: [PATCH 27/36] tty: synclinkmp: Mark never checked 'readval' as __always_unused
    On Thu, 05 Nov 2020, David Laight wrote:

    > > >> And the loop can be turned into ndelay:
    > > >>
    > > >> /*
    > > >> * Force at least 170ns delay before clearing
    > > >> * reset bit. Each read from LCR takes at least
    > > >> * 30ns so 10 times for 300ns to be safe.
    > > >> */
    > > >> for(i=0;i<10;i++)
    > > >> readval = *MiscCtrl;
    > > >
    > > > Again, since I can't test this, I do not want this patch to contain
    > > > any functional changes. AFAIC, the 10 register reads must still
    > > > happen after this patch is applied.
    >
    > You can't use ndelay(); the writes can get posted so can appear
    > much closer together by the time they get to the actual hardware.
    > Multiple volatile reads don't need a target variable.
    > (Shouldn't they also real readl()?)
    >
    > Deleting the driver works...

    Will post the removal patches when my tests finish.

    --
    Lee Jones [李琼斯]
    Senior Technical Lead - Developer Services
    Linaro.org │ Open source software for Arm SoCs
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