On 27.01.2017 21:40, Georg Chini wrote: > On 03.01.2017 18:17, Tanu Kaskinen wrote: >> On Thu, 2016-12-15 at 12:34 +0530, Renjith Thomas wrote: >>> Issue: When HFP/HSP profile is used with certain BT chipsets, the >>> audio sounds heavily distorted, with very slow playback full of noise. >>> During recording, the samples are dropped and it distorts the recorded >>> audio samples. >>> >>> The root cause of both the issues are related to the fixed MTU sizes >>> in the PA stack, which is 48 bytes. Here, the BT chipset CC256x had >>> 180 bytes MTU and it was being under-utilized and the rate at which >>> the samples were being accepted where not matching the expected rate, >>> and hence the distortion. >>> >>> Solution: The appropriate solution to this problem is by reading the >>> MTU size of the SCO socket using getsockopts dynamically. >>> >>> BugLink: http://bit.ly/2gDpGPv >>> BugLink: http://bit.ly/2hQsARK >>> --- >>> src/modules/bluetooth/backend-native.c | 28 >>> ++++++++++++++++++---------- >>> 1 file changed, 18 insertions(+), 10 deletions(-) >> Thanks! Applied to the "next" branch. >> > Hi, > > this patch breaks HSP for me. My headset (Plantonics Backbeat Pro) > returns an MTU of 64, but it looks like this is only working for > recording. > When I try to play back something, I cannot hear any sound and the > headset disconnects after a few seconds. > > When I set omtu to 48, everything is working again. Tested a second headset - same result. The headset returns 64 as MTU but only works if I set omtu to 48. Should the patch be reverted or modified to change only imtu? Can anyone else confirm my problem? Regards Georg
