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    SubjectRe: [PATCH v5 1/2] mfd: Add anatop mfd driver
    On Thu, Mar 01, 2012 at 05:10:51PM +0800, Ying-Chun Liu (PaulLiu) wrote:

    > + spin_lock(&adata->reglock);
    > + val = readl(adata->ioreg + addr);
    > + spin_unlock(&adata->reglock);

    Do you really need to take a lock for a single read operation from a
    memory mapped register? I'd expect this to be atomic in itself. You
    need to lock on read/modify/write cycles to make sure that you don't get
    a read/read/modify/modify/write/write and misplace one of the modifies
    but that's not an issue for an isolated read.
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      Last update: 2012-03-01 12:33    [W:0.018 / U:46.448 seconds]
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