From: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
To: Nicolas Morey-Chaisemartin <nmorey@kalray.eu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [Question] Missing data after DMA read transfer
Date: Thu, 21 Apr 2016 09:35:12 +0100 [thread overview]
Message-ID: <20160421093512.4a63e2c2@lxorguk.ukuu.org.uk> (raw)
In-Reply-To: <0ae37751-a824-7ac7-6723-66142d5d861c@kalray.eu>
> But if I try to copy_from_user (using the address coming from userland, the one passed to get_user_pages), the data has not been written and I see the memset value.
>
> I manage to build a test case that fails all the time, but never at the same offset within the buffer.
> It's always in the middle (never at the start nor end), for a few pages long (varies between runs).
Always page aligned, always cache line aligned or arbitrarily aligned ?
Alan
next prev parent reply other threads:[~2016-04-21 8:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-20 14:56 Nicolas Morey-Chaisemartin
2016-04-21 8:35 ` One Thousand Gnomes [this message]
2016-04-21 8:51 ` Nicolas Morey-Chaisemartin
2016-04-25 6:18 ` Nicolas Morey-Chaisemartin
2016-04-26 13:31 ` Nicolas Morey-Chaisemartin
2016-04-27 9:20 ` Nicolas Morey-Chaisemartin
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