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From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Arend van Spriel <arend@broadcom.com>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Brett Rudley <brudley@broadcom.com>,
	Henry Ptasinski <henryp@broadcom.com>,
	Roland Vossen <rvossen@broadcom.com>,
	"Franky (Zhenhui) Lin" <frankyl@broadcom.com>
Subject: Re: brcmsmac hangs machine if loaded after busmastering disabled
Date: Wed, 18 Apr 2012 13:34:49 +0100	[thread overview]
Message-ID: <20120418123449.GB26953@srcf.ucam.org> (raw)
In-Reply-To: <4F8EA657.7020006@broadcom.com>

On Wed, Apr 18, 2012 at 01:32:39PM +0200, Arend van Spriel wrote:
> I discussed this with hardware designer and here is his quote "You
> would need to disable the DMA engines before disable PCIe master
> mode. If you didn't do that, and the DMA engines were active, the
> MAC would almost certainly hang."
> 
> So disabling the master mode solved your memory corruption, but the
> chip will hang. The DMA engines mentioned are the on-chip engines.
> As you indicated you can only use common PCI operations so I do not
> expect disabling BAR decoding will solve the hang in the chip.

Yeah, I can get away with putting generic PCI operations in the 
bootloader, but a specific Broadcom driver is probably going a bit 
far...

> Only as an experiment you could try to reset the device toggling the
> pci power state.

Should putting the PCI device in D3 be sufficient for this, or would I 
also need to touch any state in the 802.11 core?

-- 
Matthew Garrett | mjg59@srcf.ucam.org

  reply	other threads:[~2012-04-18 12:34 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-19 21:51 Matthew Garrett
2012-04-11 11:45 ` brcmsmac hangs machine if loaded after busmastering disabled Arend van Spriel
2012-04-11 11:51   ` Matthew Garrett
2012-04-18 11:32     ` Arend van Spriel
2012-04-18 12:34       ` Matthew Garrett [this message]
2012-04-18 15:29         ` Arend van Spriel
2012-04-18 15:37           ` Matthew Garrett
2012-04-18 16:35             ` Arend van Spriel

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