On Mon, 08 Oct 2018 11:34:12 +0200, Mark Brown wrote: > > On Fri, Oct 05, 2018 at 12:14:03PM -0400, Sasha Levin wrote: > > From: Yu Zhao <yuzhao@xxxxxxxxxx> > > > > [ Upstream commit b61749a89f826eb61fc59794d9e4697bd246eb61 ] > > > > In snd_hdac_bus_init_chip(), we enable interrupt before > > snd_hdac_bus_init_cmd_io() initializing dma buffers. If irq has > > been acquired and irq handler uses the dma buffer, kernel may crash > > when interrupt comes in. > > CCing Takashi who's the maintainer here for review. This is OK to take as a stable. This shouldn't break, at least. thanks, Takashi > > > > Fix the problem by postponing enabling irq after dma buffer > > initialization. And warn once on null dma buffer pointer during the > > initialization. > > > > Reviewed-by: Takashi Iwai <tiwai@xxxxxxx> > > Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx> > > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> > > Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> > > --- > > sound/hda/hdac_controller.c | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c > > index 560ec0986e1a..11057d9f84ec 100644 > > --- a/sound/hda/hdac_controller.c > > +++ b/sound/hda/hdac_controller.c > > @@ -40,6 +40,8 @@ static void azx_clear_corbrp(struct hdac_bus *bus) > > */ > > void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus) > > { > > + WARN_ON_ONCE(!bus->rb.area); > > + > > spin_lock_irq(&bus->reg_lock); > > /* CORB set up */ > > bus->corb.addr = bus->rb.addr; > > @@ -479,13 +481,15 @@ bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset) > > /* reset controller */ > > azx_reset(bus, full_reset); > > > > - /* initialize interrupts */ > > + /* clear interrupts */ > > azx_int_clear(bus); > > - azx_int_enable(bus); > > > > /* initialize the codec command I/O */ > > snd_hdac_bus_init_cmd_io(bus); > > > > + /* enable interrupts after CORB/RIRB buffers are initialized above */ > > + azx_int_enable(bus); > > + > > /* program the position buffer */ > > if (bus->use_posbuf && bus->posbuf.addr) { > > snd_hdac_chip_writel(bus, DPLBASE, (u32)bus->posbuf.addr); > > -- > > 2.17.1 > > > [2 signature.asc <application/pgp-signature (7bit)>] >