ping packet loss of WiFi dongle in newer kernel ( 4.2.0-rc4-bone2 )

I use D-Link Corp. DWA-121 802.11n Wireless N 150 on beaglebone black RevC.
For USB hotplug purpose, I update my kernel to EXPERIMENTAL 4.2.0-rc4-bone2 and TESTING 4.1.0-rc8-bone9.

However, I found that on newer version compared to STABLE 3.8.13-bone73 , ping packet loss rate is higher.

some packets response "“Destination Host Unreachable”
Anyone having idea or have similar problems?

Newer kernel seems use different drivers and firmware for RealTek Wifi dongle

root@beaglebone:~# lsmod
Module Size Used by
ccm 6428 2
snd_usb_audio 126178 0
snd_hwdep 5214 1 snd_usb_audio
snd_usbmidi_lib 18550 1 snd_usb_audio
snd_seq_midi 5191 0
snd_seq_midi_event 5886 1 snd_seq_midi
snd_rawmidi 18468 2 snd_usbmidi_lib,snd_seq_midi
snd_pcm 75793 1 snd_usb_audio
snd_seq 46830 2 snd_seq_midi_event,snd_seq_midi
snd_seq_device 4677 3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer 16631 2 snd_pcm,snd_seq
evdev 8213 1
snd 57253 8 snd_usb_audio,snd_hwdep,snd_timer,snd_pcm,snd_seq,snd_rawmidi,snd_usbmidi_lib,snd_seq_device
uvcvideo 61665 0
videobuf2_vmalloc 5145 1 uvcvideo
videobuf2_memops 2708 1 videobuf2_vmalloc
videobuf2_core 34201 1 uvcvideo
soundcore 6742 1 snd
arc4 1966 2
rtl8192cu 53656 0
rtl_usb 8276 1 rtl8192cu
rtl8192c_common 38645 1 rtl8192cu
rtlwifi 53884 3 rtl_usb,rtl8192c_common,rtl8192cu
mac80211 473394 3 rtl_usb,rtlwifi,rtl8192cu
cfg80211 385338 2 mac80211,rtlwifi
pvrsrvkm 148041 0
omap_aes 12439 0
omap_sham 20563 0
usb_f_acm 6828 1
u_serial 9602 3 usb_f_acm
usb_f_ecm 9066 1
g_multi 5942 0
usb_f_mass_storage 40238 2 g_multi
usb_f_rndis 20474 2 g_multi
u_ether 10985 3 usb_f_ecm,usb_f_rndis,g_multi
libcomposite 43358 5 usb_f_acm,usb_f_ecm,usb_f_rndis,g_multi,usb_f_mass_storage
tda998x 11577 0
tilcdc 24624 0
omap_rng 4264 0
drm_kms_helper 103830 4 tda998x,tilcdc
rng_core 7113 1 omap_rng
uio_pdrv_genirq 3321 0
uio 8146 1 uio_pdrv_genirq
leds_gpio 3186 0

stable Kernel

root@beaglebone:~# lsmod
Module Size Used by
uvcvideo 57013 0
snd_usb_audio 100405 0
videobuf2_vmalloc 2490 1 uvcvideo
snd_hwdep 4885 1 snd_usb_audio
snd_usbmidi_lib 15375 1 snd_usb_audio
8192cu 449033 0
g_multi 50407 2
libcomposite 15028 1 g_multi
omap_rng 4062 0
mt7601Usta 458758 0

regards,
Ivan

Please retest with: 4.1.3-ti-r6

cd /opt/scripts/tools/
git pull

sudo ./update_kernel.sh --ti-kernel --beta

I use D-Link Corp. DWA-121 802.11n Wireless N 150 on beaglebone black RevC.
For USB hotplug purpose, I update my kernel to EXPERIMENTAL 4.2.0-rc4-bone2
and TESTING 4.1.0-rc8-bone9.
However, I found that on newer version compared to STABLE 3.8.13-bone73 ,
ping packet loss rate is higher.
some packets response ""Destination Host Unreachable"
Anyone having idea or have similar problems?

Please retest with: 4.1.3-ti-r6

cd /opt/scripts/tools/
git pull

sudo ./update_kernel.sh --ti-kernel --beta

Then create a file /etc/modprobe.d/8192cu.conf with the following contents:

options 8192cu rtw_power_mgnt=0 rtw_enusbss=0

This prevents the power down/up cycles of the 8192 wifi chip.

Regards,

Sorry this ^8192cu step was for the old driver, for the mainline just:

sudo iwconfig wlan0 power off

to disable power managment...

Regards,

`

root@beaglebone:~# sudo iwconfig wlan0 power off
Error for wireless request “Set Power Management” (8B2C) :
SET failed on device wlan0 ; Operation not supported.
`

My device does not seem to support power management. But I also will try if the problem exist in this kernel.
Please wait for my results

RobertCNelson於 2015年7月30日星期四 UTC+8上午9時02分47秒寫道:

thank, now, the result looks better in kernel 4.1.3-ti-r6
any related patches on 4.1.3-ti-r6?

Sina Chou於 2015年7月30日星期四 UTC+8上午10時09分09秒寫道: