• Sergei Shtylyov's avatar
    mmc: tmio_mmc_dma: fix PIO fallback on SDHI · f936f9b6
    Sergei Shtylyov authored
    I'm testing SH-Mobile SDHI driver in DMA mode with  a new DMA controller  using
    'bonnie++' and getting DMA error after which the tmio_mmc_dma.c code falls back
    to PIO but all commands time out after that.  It turned out that the fallback
    code calls tmio_mmc_enable_dma() with RX/TX channels already freed and pointers
    to them cleared, so that the function bails out early instead  of clearing the
    DMA bit in the CTL_DMA_ENABLE register. The regression was introduced by commit
    162f43e3 (mmc: tmio: fix a deadlock).
    Moving tmio_mmc_enable_dma() calls to the top of the PIO fallback code in
    tmio_mmc_start_dma_{rx|tx}() helps.
    Signed-off-by: default avatarSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
    Acked-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
    Cc: stable@vger.kernel.org # 3.1+
    Signed-off-by: default avatarChris Ball <cjb@laptop.org>
    f936f9b6
tmio_mmc_dma.c 8.67 KB