This is the mail archive of the
ecos-bugs@sourceware.org
mailing list for the eCos project.
[Bug 1001879] New: Kinetis DSPI infinite polling
- From: bugzilla-daemon at bugs dot ecos dot sourceware dot org
- To: ecos-bugs at ecos dot sourceware dot org
- Date: Tue, 09 Jul 2013 17:53:50 +0000
- Subject: [Bug 1001879] New: Kinetis DSPI infinite polling
- Auto-submitted: auto-generated
Please do not reply to this email, use the link below.
http://bugs.ecos.sourceware.org/show_bug.cgi?id=1001879
Bug ID: 1001879
Summary: Kinetis DSPI infinite polling
Product: eCos
Version: CVS
Target: freescale_twr_k70f120m (Freescale Kinetis TWR-K70F120M
board)
Architecture/Host Cortex-M
OS:
Status: UNCONFIRMED
Severity: normal
Priority: low
Component: SPI
Assignee: unassigned@bugs.ecos.sourceware.org
Reporter: mjones@linear.com
CC: ecos-bugs@ecos.sourceware.org
Created attachment 2322
--> http://bugs.ecos.sourceware.org/attachment.cgi?id=2322&action=edit
DSPI Polling Patch
I believe I have found the source of all my intermittent MMC/SD problems
discussed in bug 10011764. (Note, this does not apply to the 4GB Samsung Card
issue) I was fortunate to finally have a persistent failure that I could debug.
The problem is related to polling in file api_freescale_spi.c.
There is a function called dspi_transaction_end(...) and this function has the
following code:
DSPI_EOQ_CLEAR(dspi_p);
while(!(dspi_p->sr & FREESCALE_DSPI_SR_EOQF_M));
Sometimes execution hangs on the while.
I believe the problem is that the clear sometimes clears before the bit is set,
and sometimes it clears after. There is a race condition between the code and
the peripheral.
I believe the code should be:
while(!(dspi_p->sr & FREESCALE_DSPI_SR_EOQF_M));
DSPI_EOQ_CLEAR(dspi_p);
which clears the bit after the polling is satisfied.
As soon as I made this change, all my problems disappeared. I verified that my
application can now read/write the SD. My application that logs telemetry to SD
will now run for a long time without failure. I retested several SD cards and
they are fine.
--
You are receiving this mail because:
You are on the CC list for the bug.