Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On Fri, 2010-03-19 at 16:56 +0100, Joerg Albert wrote: I looked closer at the PCB and it turned out that we have a voltage divider with two 5.6 kOhm to V_3_3 and GND (R613, R614) and a capacitor C496 (!) towards the CPU. The signal at the CPU looked fine for a 2.5V TTL. The voltage drift seen above is probably caused by the capacitor unloading when the CPU pin is driven down. Curious design choice. Works fine for continuous signals at higher frequencies, but not here. I removed the resitors and replaced C496 by a 1k resistor (to protect the CPU pin against shorts). This solved my problem. I guess the above schematics was meant to be a cheap TTL level conversion 2.5V - 3.3V. Thanks for sending me again to the oscilloscope! I'm happy it is solved now. Maybe you can document this in relevant places on the web. Bas. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On Thu, 2010-03-18 at 23:04 +0100, Joerg Albert wrote: On 03/15/2010 09:33 AM, Bas Mevissen wrote: Do you have access to an oscilloscope? It might be that the signal level or signal shape is not perfect. I've seen mixed results with various serial to USB adapters too. I used an oscilloscope yesterday and the signal looked fine (sharp edges, correct timing, low noise). What were the voltages of both 0's and 1's? It's a rather new device and I run the board at home at a laboratory power supply. That should be fine. Bas. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
Hi, On 03/19/2010 10:14 AM, Bas Mevissen wrote: On Thu, 2010-03-18 at 23:04 +0100, Joerg Albert wrote: On 03/15/2010 09:33 AM, Bas Mevissen wrote: Do you have access to an oscilloscope? It might be that the signal level or signal shape is not perfect. I've seen mixed results with various serial to USB adapters too. I used an oscilloscope yesterday and the signal looked fine (sharp edges, correct timing, low noise). What were the voltages of both 0's and 1's? I attached an oscilloscope today again and saw some strange voltage levels (wonder why I missed them in the first place): If the TX (from the target to the PC) starts after some quiet period, high is at 1.7V and low at -0.6V. Both get slowly better (2.5/0) with some chars transmitted, but the first levels are definitely wrong. I looked closer at the PCB and it turned out that we have a voltage divider with two 5.6 kOhm to V_3_3 and GND (R613, R614) and a capacitor C496 (!) towards the CPU. The signal at the CPU looked fine for a 2.5V TTL. The voltage drift seen above is probably caused by the capacitor unloading when the CPU pin is driven down. I removed the resitors and replaced C496 by a 1k resistor (to protect the CPU pin against shorts). This solved my problem. I guess the above schematics was meant to be a cheap TTL level conversion 2.5V - 3.3V. Thanks for sending me again to the oscilloscope! Jörg. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
Hi Ulf, On 03/15/2010 11:31 AM, ulf kypke wrote: does this prolific has only 3 lines (rx, tx, ground) and no 3.3volt, if so, use a 1K resistor and connect the tplinks 3.3volt to rx, this might stabilize it. I tried two of the black boxes once sold at c-base (BenQ boot cable). I'd rather try to find and add the Vcc_3V3 line first before adding a pull-up on Rx. an other trick is to use a transformer 12volt power adapter not a ac/dc switching power adapter and if you do this on your laptop, unplug it from ac to run on battery power. with some devices i got better results in this way. Noise on the ground line? I tried a lab power supply instead of the 9V wallplug, no avail. i'm still looking for a very good 3.3v serial adapter, the prolific is not the best one. What about the OTI6858 used in some mobile phone data cables? Unfortunately mine broke recently. I ordered a new cable and got a PL2303 inside (but with a Vcc wire). I got a FTDI FT2232D DIP module here as well - meant to be used in a JTAG/RS232 adapter sometime. But this one still misses the adapter board. Regards, Jörg. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On Sat, 2010-03-13 at 18:31 +0100, Joerg Albert wrote: BTW, I get some garbled chars on TX (target - PC) from the WR741ND on the serial line. Both in bootloader and Linux system, so I guess it's a hardware problem (especially as the log in https://forum.openwrt.org/viewtopic.php?pid=102069#p102069 looks fine). I use a Prolific PL2303 serial USB adapter which works fine with other hardware. Someone else? Do you have access to an oscilloscope? It might be that the signal level or signal shape is not perfect. I've seen mixed results with various serial to USB adapters too. You can also try to replace the net adapter of the board. These adapters tend to age and perform worse. Bas. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
hi jörg, 2010/3/15 Bas Mevissen ab...@basmevissen.nl: On Sat, 2010-03-13 at 18:31 +0100, Joerg Albert wrote: BTW, I get some garbled chars on TX (target - PC) from the WR741ND on the serial line. Both in bootloader and Linux system, so I guess it's a hardware problem (especially as the log in https://forum.openwrt.org/viewtopic.php?pid=102069#p102069 looks fine). I use a Prolific PL2303 serial USB adapter which works fine with other hardware. Someone else? does this prolific has only 3 lines (rx, tx, ground) and no 3.3volt, if so, use a 1K resistor and connect the tplinks 3.3volt to rx, this might stabilize it. an other trick is to use a transformer 12volt power adapter not a ac/dc switching power adapter and if you do this on your laptop, unplug it from ac to run on battery power. with some devices i got better results in this way. i'm still looking for a very good 3.3v serial adapter, the prolific is not the best one. regards ulf ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On Mon, 2010-03-15 at 11:31 +0100, ulf kypke wrote: i'm still looking for a very good 3.3v serial adapter, the prolific is not the best one. Best trick is to cascade a MAX3232 level shifter with 3V3 power supply. It will raise the signal level to just over 5V. That is enough for the average serial-to-USB converter. It also protects the other end from over voltage. I once had to couple an AVR32 development board to an automotive GSM modem using a bi-directional cascade of 3V3 and 5V powered MAX3232 level shifters... Bas. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On Mon, 2010-03-15 at 09:33 +0100, Bas Mevissen wrote: On Sat, 2010-03-13 at 18:31 +0100, Joerg Albert wrote: I use a Prolific PL2303 serial USB adapter which works fine with other hardware. Someone else? Do you have access to an oscilloscope? It might be that the signal level or signal shape is not perfect. I've seen mixed results with various serial to USB adapters too. You can also try to replace the net adapter of the board. These adapters tend to age and perform worse. The PL2303 data sheet says RS232-like in about a million places where one may rather see actual RS232. I suspect a PL2303 running off 5V USB supply voltage may only pump -10v/10v signal levels (similar to some Maxim chips which have a simple doubling charge pump), and some devices may not do too well at the 2v difference, even though the RS232 spec I believe states a range between 10 and 12 as within the limits. Either way, it could be marginal depending on the other transceivers involved. The Maxim chips will work down to -9v/9v or so and seem to be some of the most tolerant of voltage or dirty signal - so the other suggestion about double shifting via cascaded Maxim chips is probably a great way to recondition the signal if the PL2303 RS232-like output is not quite RS232-enough for your equipment. ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
On 03/02/2010 12:04 AM, Dennis Bartsch wrote: But my question is left to be answered. Does this bridge which is created over the LAN-ports really mean that the CPU is doing the bridging?? Performance-wise this would be a bad behaviour. Looks like this. With svn r20176 and two PC on LAN ports the PC are no longer connected if I break the bridge with ifconfig br-lan down brctl delbr br-lan I guess we need swconfig support for the built-in switch (if possible). I'll try to adapt the 8216 code. BTW, I get some garbled chars on TX (target - PC) from the WR741ND on the serial line. Both in bootloader and Linux system, so I guess it's a hardware problem (especially as the log in https://forum.openwrt.org/viewtopic.php?pid=102069#p102069 looks fine). I use a Prolific PL2303 serial USB adapter which works fine with other hardware. Someone else? ___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
Hi
On 13 March 2010 18:31, Joerg Albert j...@gmx.de wrote:
I guess we need swconfig support for the built-in switch (if possible). I'll
try to adapt the 8216
code.
I am currently adapting the ar8216 driver to support the ar8316[1],
and therefore it probably the best to combine the effort (and there
won't be a race whose patch gets accepted first ;-).
As far as I can see, the internal switch of the ar7240 is basically an
ar8216, but with a gigabit mii connection on the cpu port.
I am currently identifying the chip through the version and revision
fields of the control register (0x), where the ar8216 is 1/1, the
ar8316 is 16/1.
As far as I can see in the dsa driver, the version of the ar7240 is
also 1, but I lack the revision information.
('Though it could be assumed through the phy_device being connected
with a gigabit mii connection).
OTOH, the DSA switching architecture looks like the right way to do
it, but currently lacks too many features.
There is a patch for hardware bridging support for DSA[2], but its
already over a year old, and got never applied. But this might be
worth a shot to try to add that to OpenWRT and adapt the ar7240 dsa
driver to it.
Best regards,
Jonas Gorski
[1] https://forum.openwrt.org/viewtopic.php?pid=104435#p104435 and
following posts
[2] http://patchwork.ozlabs.org/patch/16578/
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Re: [OpenWrt-Devel] AR7240 switch // was: TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU
Hello list, finally the switch in the TP-Link TL-WR741N(D) (and probably other devices based von AR7140) is not blocking broadcasts any more and thus allows to get an IP via DHCP. But my question is left to be answered. Does this bridge which is created over the LAN-ports really mean that the CPU is doing the bridging?? Performance-wise this would be a bad behaviour. Regards Dennis From: dennis_bart...@hotmail.com To: openwrt-devel@lists.openwrt.org Date: Mon, 1 Mar 2010 21:47:44 +0100 Subject: Re: [OpenWrt-Devel] TP-Link TL-WR741ND: broadcasts on ethernet not reaching CPU Hello From: j...@gmx.de I couldn't find any code in svn r19920 dealing specifically with the AR7240 and the built-in switch. Today in revision 19927 switch support for AG7240 has been committed. I'll try that. Buildroot is running at the moment. So I guess that the bootloader settings of the switch stay valid. In the u-boot sources from the TP-Link tar ball you find in board/ar7240/common/ar7240_s26_phy.c, line 345: /* Enable ARP packets to CPU port */ athrs26_reg_write(S26_ARL_TBL_CTRL_REG,(athrs26_reg_read(S26_ARL_TBL_CTRL_REG) | 0x10)); Maybe other broadcast packets need to be enabled here, too? could be an explanation. What I understand from the commit 19930 is, that bridging is now done in CPU on this switch? Am I right? [...] Regards, Joerg. Regards, Dennis Herzig: Verschicke fertige Liebesgrüße als E-Mail! _ http://redirect.gimas.net/?n=M1002xHMNoSpam2 Keine Lust auf Spam? Hotmail blockiert Spam automatisch___ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
