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    Subject[PATCH 3.16 098/410] spi: imx: do not access registers while clocks disabled
    3.16.57-rc1 review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Stefan Agner <stefan@agner.ch>

    commit d593574aff0ab846136190b1729c151c736727ec upstream.

    Since clocks are disabled except during message transfer clocks
    are also disabled when spi_imx_remove gets called. Accessing
    registers leads to a freeeze at least on a i.MX 6ULL. Enable
    clocks before disabling accessing the MXC_CSPICTRL register.

    Fixes: 9e556dcc55774 ("spi: spi-imx: only enable the clocks when we start to transfer a message")
    Signed-off-by: Stefan Agner <stefan@agner.ch>
    Signed-off-by: Mark Brown <broonie@kernel.org>
    [bwh: Backported to 3.16: adjust context]
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    drivers/spi/spi-imx.c | 15 +++++++++++++--
    1 file changed, 13 insertions(+), 2 deletions(-)

    --- a/drivers/spi/spi-imx.c
    +++ b/drivers/spi/spi-imx.c
    @@ -943,12 +943,23 @@ static int spi_imx_remove(struct platfor
    {
    struct spi_master *master = platform_get_drvdata(pdev);
    struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
    + int ret;

    spi_bitbang_stop(&spi_imx->bitbang);

    + ret = clk_enable(spi_imx->clk_per);
    + if (ret)
    + return ret;
    +
    + ret = clk_enable(spi_imx->clk_ipg);
    + if (ret) {
    + clk_disable(spi_imx->clk_per);
    + return ret;
    + }
    +
    writel(0, spi_imx->base + MXC_CSPICTRL);
    - clk_unprepare(spi_imx->clk_ipg);
    - clk_unprepare(spi_imx->clk_per);
    + clk_disable_unprepare(spi_imx->clk_ipg);
    + clk_disable_unprepare(spi_imx->clk_per);
    spi_master_put(master);

    return 0;
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