From: Rander Wang rander.wang@linux.intel.com

Fix potential DMA hang upon starting playback on devices in HDA mode on Intel platforms (Gemini Lake/Whiskey Lake/Comet Lake/Ice Lake). It doesn't affect platforms before Gemini Lake or any Intel device in non-HDA mode.

The reset value for the LOSDIV register is all output streams valid. Clear this register to invalidate non-existent streams when the bus is powered up.

Signed-off-by: Rander Wang rander.wang@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- include/sound/hda_register.h | 3 +++ sound/hda/ext/hdac_ext_controller.c | 5 +++++ 2 files changed, 8 insertions(+)

diff --git a/include/sound/hda_register.h b/include/sound/hda_register.h index 0fd39295b426..057d2a2d0bd0 100644 --- a/include/sound/hda_register.h +++ b/include/sound/hda_register.h @@ -264,6 +264,9 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 }; #define AZX_REG_ML_LOUTPAY 0x20 #define AZX_REG_ML_LINPAY 0x30

+/* bit0 is reserved, with BIT(1) mapping to stream1 */ +#define ML_LOSIDV_STREAM_MASK 0xFFFE + #define ML_LCTL_SCF_MASK 0xF #define AZX_MLCTL_SPA (0x1 << 16) #define AZX_MLCTL_CPA (0x1 << 23) diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c index 211ca85acd8c..cfab60d88c92 100644 --- a/sound/hda/ext/hdac_ext_controller.c +++ b/sound/hda/ext/hdac_ext_controller.c @@ -270,6 +270,11 @@ int snd_hdac_ext_bus_link_get(struct hdac_bus *bus,

ret = snd_hdac_ext_bus_link_power_up(link);

+ /* + * clear the register to invalidate all the output streams + */ + snd_hdac_updatew(link->ml_addr, AZX_REG_ML_LOSIDV, + ML_LOSIDV_STREAM_MASK, 0); /* * wait for 521usec for codec to report status * HDA spec section 4.3 - Codec Discovery