From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
To: David Brownell <david-b@pacbell.net>,
spi-devel-general@lists.sourceforge.net,
linux-kernel@vger.kernel.org
Subject: spi transfer with zero length
Date: Sat, 16 Feb 2008 23:02:32 +0900 (JST) [thread overview]
Message-ID: <20080216.230232.25478328.anemo@mba.ocn.ne.jp> (raw)
Hi. Is it legal to use zero for 'len' field of struct spi_transfer?
I mean, len=0, tx_buf=rx_buf=NULL, delay_usecs!=0.
Some SPI devices need slightly long delay before first CLK edge after
CS assertion. To achieve this, I think inserting using a zero length
transfer before real transfers. But it seems some drivers do not
handle this case properly.
Is this driver's bug, or we need additional delay field in struct
spi_device for such case?
---
Atsushi Nemoto
next reply other threads:[~2008-02-16 14:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-16 14:02 Atsushi Nemoto [this message]
2008-02-16 18:58 ` David Brownell
2008-02-17 14:16 ` Atsushi Nemoto
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