All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jared Bents <jared.bents@rockwellcollins.com>
To: ath10k@lists.infradead.org
Subject: DMA issues on PowerPC64
Date: Fri, 9 Mar 2018 09:08:29 -0600	[thread overview]
Message-ID: <CAM=7fbewAQ7tW7J4fbq811a4++H+RMz0oxC9KiOsZnPFFQcuNQ@mail.gmail.com> (raw)

Hi all,

Some background information first.  I transitioned a build from 32 bit
to 64 bit and discovered my wifi modules no longer work.  I am using
fsl-v2.0-1703 on a qoriq t1042.  I sourced the problem to DMA mapping
errors and found that it was trying to map addresses in regions not
allowed by the kernel.

ath10k_pci 0001:01:00.0: unable to get target info from device
ath10k_pci 0001:01:00.0: could not get target info (5)
ath10k_pci 0001:01:00.0: could not probe fw (5)


I discovered that if I limited my memory from the actual 8GB present
down to just 2GB with the bootarg mem=2048M, the ath10k modules
worked.

So I started poking around in ath10k/pci.c and noticed that if I ORed
the regions specified in the memory allocations with GFP_DMA, I could
get rid of the initial dma mapping errors.  A couple of examples are
below.

skb = __dev_alloc_skb(pipe->buf_sz, GFP_DMA | GFP_ATOMIC);
treq = kmemdup(req, req_len, GFP_DMA | GFP_KERNEL);


But then came across these failures which I have yet to sort out.

ath10k_pci 0001:01:00.0: failed to connect htt (-5)
ath10k_pci 0001:01:00.0: could not init core (-5)
ath10k_pci 0001:01:00.0: could not probe fw (-5)


I am wondering if anyone else has come across this issue and solved it
or if somehow this is just an issue on ppc64 and I am somehow the only
one in that use case.  Unfortunately because of the qoriq t1042, I am
on the latest kernel I can use via the latest available sdk for my
processor which is linux kernel version 4.1.35-rt41

Thank you,
Jared

_______________________________________________
ath10k mailing list
ath10k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath10k

             reply	other threads:[~2018-03-09 15:08 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-09 15:08 Jared Bents [this message]
2018-03-10  9:24 ` DMA issues on PowerPC64 Kalle Valo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAM=7fbewAQ7tW7J4fbq811a4++H+RMz0oxC9KiOsZnPFFQcuNQ@mail.gmail.com' \
    --to=jared.bents@rockwellcollins.com \
    --cc=ath10k@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.