From: linus.ml.walleij@gmail.com (Linus Walleij)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 5/6] ARM: PL011: Add support for transmit DMA
Date: Wed, 29 Dec 2010 01:50:37 +0100 [thread overview]
Message-ID: <AANLkTikkjd-j5MUcP254chPpWKpiQ_nh3ZjWz2OPEJVA@mail.gmail.com> (raw)
In-Reply-To: <E1PW4qN-0006GS-EM@rmk-PC.arm.linux.org.uk>
2010/12/24 Russell King - ARM Linux <linux@arm.linux.org.uk>:
> - remove RX DMA support. ?As PL011 doesn't give us receive timeout
> ?interrupts, we only get notified of received data when the RX DMA
> ?has completed. ?This rather sucks for interactive use of the TTY.
True for use with PL08x.
But for the systems U300 and Ux500 that have (only) burst
transfer support (such is the nature of their DMA engines) it will
likely work.
However it's OK for the time being, this is such a large step
forward for us anyway, and we can surely put in a new
patch for this only and discuss it... My idea would be not to
supply any RX channel playform data for hardware that cannot
handle this and in that case fall back to PIO for RX.
Yours,
Linus Walleij
next prev parent reply other threads:[~2010-12-29 0:50 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-24 10:23 [PATCH 0/6] PL011 DMA support Russell King - ARM Linux
2010-12-24 10:24 ` [PATCH 1/6] ARM: PL011: Ensure error flags are clear at startup Russell King - ARM Linux
2010-12-24 10:24 ` [PATCH 2/6] ARM: PL011: Separate hardware FIFO size from TTY FIFO size Russell King - ARM Linux
2010-12-24 10:25 ` [PATCH 3/6] ARM: PL011: Ensure IRQs are disabled in UART interrupt handler Russell King - ARM Linux
2010-12-24 10:25 ` [PATCH 4/6] ARM: PL011: Allow better handling of vendor data Russell King - ARM Linux
2010-12-24 10:25 ` [PATCH 5/6] ARM: PL011: Add support for transmit DMA Russell King - ARM Linux
2010-12-29 0:50 ` Linus Walleij [this message]
2010-12-24 10:26 ` [PATCH 6/6] ARM: PL011: add DMA burst threshold support for ST variants Russell King - ARM Linux
2010-12-29 0:53 ` [PATCH 0/6] PL011 DMA support Linus Walleij
-- strict thread matches above, loose matches on Subject: below --
2010-12-22 23:10 [PATCH 5/6] ARM: PL011: Add support for transmit DMA Russell King - ARM Linux
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