topic Re: MCF547x/8x & Linux v2.6.10 Stability Problems in ColdFire/68K Microcontrollers and Processors

MCF547x/8x & Linux v2.6.10 Stability Problems

TonyM — Mon, 29 Oct 2007 20:20:34 GMT

The MCF547x with Linux v2.6.10 Kernel from the Freescale BSP release has surfaced what appears to be kernel stability issues. We're spotting intermittent problems in JFFS2 and also in softIRQ with tasklet_action. There are other issues with just complete system lockup but it's not confirmed whether or not it's kernel related.

Regarding the JFFS2 issue, it was recommended that we use a more recent kernel but there doesn't seem to be anyone with a version more recent than v2.6.10 for the MCF547x series.

I notice that Freescale does have a BSP for MCF5445x with Linux v2.6.20. Are there any plans for a Linux v2.6.20 port for the MCF547x?

Tony.

Re: MCF547x/8x & Linux v2.6.10 Stability Problems

SteveJoiner — Mon, 29 Oct 2007 22:35:17 GMT

I am working on a product with a 5474 with the Freescale BSP (LTIB), and I am interested in the answer to this question as well. Hopefully, someone from Freescale will be able to let us know when the BSP will be updated.

-Steve

Re: MCF547x/8x & Linux v2.6.10 Stability Problems

TonyM — Tue, 30 Oct 2007 21:43:17 GMT

Steve, are you also experiencing kernel issues? If so, what issues have you been seeing?

Tony.

Re: MCF547x/8x & Linux v2.6.10 Stability Problems

SteveJoiner — Tue, 30 Oct 2007 23:43:07 GMT

We see kernel panics and oopses from time to time. We fixed one source of them, which was a driver that we wrote which is using an external coldfire interrupt. Those interrupts are non-maskable, which can wreak havoc with the kernel if you are not careful about how you write the driver. After fixing that, we are having less kernel panics, but still see some occasionally.

We are also seeing some occasional corruption in JFFS2 on our NAND flash. The occurances are intermittent, so it is hard to track them down, but there is definitely something going on. When bringing up JFFS2 on our NAND flash, I dug into the kernel supplied with the BSP. It seems that whoever did the BSP backported some post-2.6.10 JFFS2 stuff into this kernel. Looking at the kernel changelogs, there are lots of fixes to JFFS2 (especially for NAND flash) after 2.6.10 and 2.6.11. I would really like to see Freescale update the BSP with a recent kernel so that we could get those fixes.

Another point of frustration is the on-chip USB. There is no Linux driver for it. From the people I've talked to, it seems that Freescale is not working on a Linux driver for it. It seems like they have had some silicon problems with that peripheral, and it may be that it still isn't working yet. Unfortunately for us, the USB peripheral is one of the reasons we chose this part, and now Freescale is not even supporting it.

The poor quality of the BSP for this chip and the complete lack of support for the USB peripheral make me very reluctant to choose Freescale parts for future designs.

-Steve

Re: MCF547x/8x & Linux v2.6.10 Stability Problems

admin — Tue, 06 Nov 2007 01:01:05 GMT

You might want to check the settings for the setup of CS0 and CS1 on the FlexBus - I just ran into a problem that just surfaced for me - see my post:

http://forums.freescale.com/freescale/board/message?board.id=CFCOMM&thread.id=3412.

Note that the dBUG code that comes in the M54X5EVB eval. kit does set 1 cycle address setup time on both CS0 and CS1.

Message Edited by limeyguru on 2007-11-05 09:02 AM