"transmit timed out" on FCC in MPC8260 as well as MPC8247

"transmit timed out" on FCC in MPC8260 as well as MPC8247

[Siju Viswanath K E]

Hi,
	I am using denk's linuxppc-2.4.20 . I am getting this problem of
"transmit timed out" on FCC in MPC8260 as well as MPC8247. It seems to
be a case of late collision. I checked out earlier posts similar to this
also. The problem occurs if I attempt to transfer large files and is not
seen on all systems.

	The messages on console are given below. I am seeing the
same 5th BD reporting LC. FCC_PSMR_LPB is already set in
arch/ppc/8260_io/fcc_enet.c .

	Can the 8247 errata CPM119 or some other errata be the cause ? What is
the solution for this ?
 
console messages:
 
NETDEV WATCHDOG: eth0: transmit timed out
 
eth0: transmit timed out.
 
 Ring data dump: cur_tx c01ef560 (full) cur_rx c01ef4d0.
 
 Tx @base c01ef508 :
 
5c00 0036 016d7da2
 
1c00 003e 00c25892
 
5c00 0036 00c2529a
 
1c00 0121 066b489a
 
1c00 05ea 0652e89a
 
1c80 01f0 0652e09a
 
9c00 0056 00c25c7a
 
9c00 003e 00c25e92
 
9c00 0056 00ad527a
 
9c00 003e 00ad5092
 
dc00 0036 00ad549a
 
9c00 004e 00c25682
 
1c00 003e 00c25492
 
5c00 0036 00c25a9a
 
1c00 0123 065c009a
 
3c00 040d 066b409a
 
 Rx @base c01ef408 :
 
9c00 0040 07b34000
 
<deleted>
 
bc00 0040 07b25800
 
 
+++++++++++++++++ similar problems ++++++++++++++++++++
 
1. http://patchwork.ozlabs.org/linuxppc/patch?id=1853
 
2. From: hubert loewenguth <hubert.loewenguth@thales-bm.com>
To: linuxppc-embedded@ozlabs.org
Subject: MPC8260 fcc_enet transmit timed out
Date: Mon, 14 Nov 2005 18:34:32 +0100

<deleted>
I have found some personns in this mailling list who has encounter a
problem wich seems similar:
 
http://ozlabs.org/pipermail/linuxppc-embedded/2005-January/016539.html
http://ozlabs.org/pipermail/linuxppc-embedded/2001-December/005714.html
<deleted>
+++++++++++++++++ similar problems ++++++++++++++++++++
 
Thanks,
Siju Viswanath K E
Tejas Networks

Re: "transmit timed out" on FCC in MPC8260 as well as MPC8247

[Wolfgang Denk]

In message <1143177651.22246.3.camel@Blaze> you wrote:
>
> 	I am using denk's linuxppc-2.4.20 . I am getting this problem of

Why don't you try using a more current version of the code? 2.4.20 is
*very* old, and *lots* of bugs and problems have been fixed since.

It really does not make sense to spend effort on such old code.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
Those who do not  understand  Unix  are  condemned  to  reinvent  it,
poorly.              - Henry Spencer, University of Toronto Unix hack

Re: [BULK] Re: "transmit timed out" on FCC in MPC8260 as well as MPC8247

[Siju Viswanath K E]

Hi Denk,
	Thanks for the suggestion. I had a look at the source repository
at projects/linuxppc_2_4_devel.git site. Outdated code doesnt seem to be
the issue. My repository is patched upto 
"Patch by Wojciech Kromer, 06 Jan 2004" and later changes are only
adding extra board support. 

regards,
Siju Viswanath

On Fri, 2006-03-24 at 13:21, Wolfgang Denk wrote:
> In message <1143177651.22246.3.camel@Blaze> you wrote:
> >
> > 	I am using denk's linuxppc-2.4.20 . I am getting this problem of
> 
> Why don't you try using a more current version of the code? 2.4.20 is
> *very* old, and *lots* of bugs and problems have been fixed since.
> 
> It really does not make sense to spend effort on such old code.
> 
> Best regards,
> 
> Wolfgang Denk

Re: "transmit timed out" on FCC in MPC8260 => bug corrected

[hubert.loewenguth]

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Hi to the community.

I'm the man who has posted numerous questions about this problem of 
fcc_enet timeout in ppc8260.
I just want to say that the 2.6 kernel doesn't solve the problem if you 
have it on your board (I tried it,  normally I have a 2.4-20 linux too).
I have search for this bug during a long time, and fortunatly, I 'm 
happy to say you that finally, it is corrected since few days.
Special thanks to "Hunter, David" for having take in consideration my 
problem, and proposing me some way of invastigations in this thread:

http://ozlabs.org/pipermail/linuxppc-embedded/2006-January/021842.html

In fact the solution comes from the new "MPC8260 PowerQUICC II Family 
Reference Manual"   fresescale has delivered 01/19/2006.
http://www.freescale.com/files/product/doc/MPC8260UM.pdf

They have added a very interesting paragraph about error handling in 
ethernet mode:

/29.10.1.3 Adjusting Transmitter BD Handling
When a TXE event occurs, the TBPTR may already point beyond BDs still 
marked as ready due to internal
pipelining. If the TBPTR is not adjusted, these BDs would be skipped 
while still being marked as ready.
Software must determine if these BDs should be retransmitted or if they 
should be skipped, depending on
the protocol and application needs. This requires the following steps:
1. From the current TBPTR value, search backwards over all (if any) BDs 
still marked as ready to
find the first BD that has not been closed by the CPM. The search 
process should stop if the BD to
be checked next is not ready or if it is the most recent BD marked as 
ready by the CPU transmit
software. This is to avoid an endless loop in case the CPU software 
fills the BD ring completely.
2. A) For skipping BDs, manually close all BDs from the BD just found up 
to and including the BD
just before TBPTR. Leave the TBPTR value untouched.
B) For retransmitting BDs, change the TBPTR value to point to the BD 
just found.
/
So, here is the correction  I have done to the fcc-enet.c driver, and 
wich I'am very satsify
I have tested it on my platform which was always entering in this 
infernal timeout loop when there was successive plug/unplug during 
important data transfert.
Thanks to some trace, I have seen that, as it is said in the new manual, 
the error comes from the pipelining and a bad restart procedure in the 
driver.
(I think it is the same restart procedure in the 2.6 kernel ??? to 
verify ...)
With this correction, I have no more infernal timeout  loop.
In fact, I replace the restart procedure in the fcc_enet_interrupt 
method by this one, which respect the MPC8260 manual restart procedure:

if (must_restart) {
        volatile cpm8260_t *cp;

        /* Some transmit errors cause the transmitter to shut
         * down.  We now issue a restart transmit.  Since the
         * errors close the BD and update the pointers, the restart
         * _should_ pick up without having to reset any of our
         * pointers either.  Also, To workaround 8260 device erratum
         * CPM37, we must disable and then re-enable the transmitter
         * following a Late Collision, Underrun, or Retry Limit error.
         */
         
         // disable Transmitter
        cep->fccp->fcc_gfmr &= ~FCC_GFMR_ENT;
        udelay(10); /* wait a few microseconds just on principle */
   
        #ifdef THALES_DEBUG_TRACE
        printk("Thales restart debug trace :\n");
        printk("first dirty tx %d, final dirty_tx %d, tbptr 
%d\n",cbt_ptr2index(dev,first_bdp_dirty_tx),cbt_ptr2index(dev,cep->dirty_tx),tbptr_ptr2index(dev,ep->fen_genfcc.fcc_tbptr));
        #endif
                                   
        // RESTART TX command to the cpm
        cp = cpmp;
        cp->cp_cpcr = mk_cr_cmd(cep->fip->fc_cpmpage, 
cep->fip->fc_cpmblock,0x0c, CPM_CR_RESTART_TX) | CPM_CR_FLG;
        while (cp->cp_cpcr & CPM_CR_FLG);
       
        // Adjusting Transmitter BD Handling
        /* HLO : I do not search backwards from the current TBPTR value 
to found skip BDs, but I directly
         * adjust the tbptr value to the dirty_tx current value.
         * In case of problemes occuring, change it and do like 
indicated in 29.10.3 of MPC8260 manual
         */
        ep->fen_genfcc.fcc_tbptr = __pa(cep->dirty_tx);
       
        #ifdef THALES_DEBUG_TRACE
        printk(" Thales workaround tbptr value adjusted : 
%d\n",tbptr_ptr2index(dev,ep->fen_genfcc.fcc_tbptr));
        #endif
       
        // re-enable Transmitter       
        cep->fccp->fcc_gfmr |=  FCC_GFMR_ENT;

        }

I hope this correction will help you and the community.

Best regards


Siju Viswanath K E a écrit :

>Hi Denk,
>	Thanks for the suggestion. I had a look at the source repository
>at projects/linuxppc_2_4_devel.git site. Outdated code doesnt seem to be
>the issue. My repository is patched upto 
>"Patch by Wojciech Kromer, 06 Jan 2004" and later changes are only
>adding extra board support. 
>
>regards,
>Siju Viswanath
>
>On Fri, 2006-03-24 at 13:21, Wolfgang Denk wrote:
>  
>
>>In message <1143177651.22246.3.camel@Blaze> you wrote:
>>    
>>
>>>	I am using denk's linuxppc-2.4.20 . I am getting this problem of
>>>      
>>>
>>Why don't you try using a more current version of the code? 2.4.20 is
>>*very* old, and *lots* of bugs and problems have been fixed since.
>>
>>It really does not make sense to spend effort on such old code.
>>
>>Best regards,
>>
>>Wolfgang Denk
>>    
>>
>
>_______________________________________________
>Linuxppc-embedded mailing list
>Linuxppc-embedded@ozlabs.org
>https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>
>  
>

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Re: [BULK] Re: "transmit timed out" on FCC in MPC8260 as well as MPC8247

[Wolfgang Denk]

In message <1143193658.22246.20.camel@Blaze> you wrote:
>
> the issue. My repository is patched upto 
> "Patch by Wojciech Kromer, 06 Jan 2004" and later changes are only
> adding extra board support. 

This is definitely *not* correct. A *long* list  of  bugs  have  been
fixed in the last two years.

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
Life is a game. Money is how we keep score.              - Ted Turner

Re: [BULK] Re: "transmit timed out" on FCC in MPC8260 => bug corrected

[Siju Viswanath K E]

Thanks for the patch.. I have implemented the changes but since it is
not very frequent in my case, I dont know whether it works for me yet.

regards,
siju
On Fri, 2006-03-24 at 17:14, hubert.loewenguth wrote:
> Hi to the community.
> 
> I'm the man who has posted numerous questions about this problem of
> fcc_enet timeout in ppc8260.
> I just want to say that the 2.6 kernel doesn't solve the problem if
> you have it on your board (I tried it,  normally I have a 2.4-20 linux
> too).
> I have search for this bug during a long time, and fortunatly, I 'm
> happy to say you that finally, it is corrected since few days. 
> Special thanks to "Hunter, David" for having take in consideration my
> problem, and proposing me some way of invastigations in this thread:
> 
> http://ozlabs.org/pipermail/linuxppc-embedded/2006-January/021842.html
> 
> In fact the solution comes from the new "MPC8260 PowerQUICC II Family
> Reference Manual"   fresescale has delivered 01/19/2006.
> http://www.freescale.com/files/product/doc/MPC8260UM.pdf

Re: [BULK] Re: "transmit timed out" on FCC in MPC8260 as well as MPC8247

[Siju Viswanath K E]

On Sat, 2006-03-25 at 05:40, Wolfgang Denk wrote:
> In message <1143193658.22246.20.camel@Blaze> you wrote:
> >
> > the issue. My repository is patched upto 
> > "Patch by Wojciech Kromer, 06 Jan 2004" and later changes are only
> > adding extra board support. 
> 
> This is definitely *not* correct. A *long* list  of  bugs  have  been
> fixed in the last two years.

I meant it only regarding the timeout issue for FCC. I was not talking
about the repository in general.

regards,
Siju