From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
tony@atomide.com, balbi@ti.com, Vinod Koul <vinod.koul@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH 05/15] tty: serial: Add 8250-core based omap driver
Date: Fri, 15 Aug 2014 22:20:53 +0200 [thread overview]
Message-ID: <53EE6BA5.2060101@linutronix.de> (raw)
In-Reply-To: <20140815193352.GC17765@csclub.uwaterloo.ca>
On 08/15/2014 09:33 PM, Lennart Sorensen wrote:
>> On the other hand if you use DMA then it can handle transfers > 64bytes
>> in one go and you can start transfers while the FIFO is not completely
>> empty.
>
> You can dma more than the fifo size?
Yes. The UART asserts the DMA line as long as there is room for
$TRESHOLD number of bytes. So we never overflow the FIFO. That is why we
can't take any DMA channel but only *the* one.
>> There is patch in Greg's tty tree already where you are able to
>> configure the RX trigger level. We could wire this up once we agree
>> which levels we want support. The OMAP supports all levels from 1…63.
>
> All? or just every 4 (that's what I just read in the DRA7xx docs).
All. Take a look at the RX_TRIGGER constant while comparing source vs
manual :)
Sebastian
WARNING: multiple messages have this Message-ID (diff)
From: bigeasy@linutronix.de (Sebastian Andrzej Siewior)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 05/15] tty: serial: Add 8250-core based omap driver
Date: Fri, 15 Aug 2014 22:20:53 +0200 [thread overview]
Message-ID: <53EE6BA5.2060101@linutronix.de> (raw)
In-Reply-To: <20140815193352.GC17765@csclub.uwaterloo.ca>
On 08/15/2014 09:33 PM, Lennart Sorensen wrote:
>> On the other hand if you use DMA then it can handle transfers > 64bytes
>> in one go and you can start transfers while the FIFO is not completely
>> empty.
>
> You can dma more than the fifo size?
Yes. The UART asserts the DMA line as long as there is room for
$TRESHOLD number of bytes. So we never overflow the FIFO. That is why we
can't take any DMA channel but only *the* one.
>> There is patch in Greg's tty tree already where you are able to
>> configure the RX trigger level. We could wire this up once we agree
>> which levels we want support. The OMAP supports all levels from 1?63.
>
> All? or just every 4 (that's what I just read in the DRA7xx docs).
All. Take a look at the RX_TRIGGER constant while comparing source vs
manual :)
Sebastian
next prev parent reply other threads:[~2014-08-15 20:20 UTC|newest]
Thread overview: 154+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-15 17:42 [PATCH v7] 8250-core based serial driver for OMAP + DMA Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 01/15] tty: serial: 8250_core: allow to overwrite & export serial8250_startup() Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 02/15] tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 03/15] tty: serial: 8250_core: add run time pm Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-20 9:23 ` Frans Klaver
2014-08-20 9:23 ` Frans Klaver
2014-08-20 9:23 ` Frans Klaver
2014-08-20 9:39 ` Frans Klaver
2014-08-20 9:39 ` Frans Klaver
2014-08-20 9:39 ` Frans Klaver
2014-09-01 14:48 ` Sebastian Andrzej Siewior
2014-09-01 14:48 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 04/15] tty: serial: 8250_core: read only RX if there is something in the FIFO Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 05/15] tty: serial: Add 8250-core based omap driver Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 18:37 ` Lennart Sorensen
2014-08-15 18:37 ` Lennart Sorensen
2014-08-15 18:37 ` Lennart Sorensen
2014-08-15 19:27 ` Sebastian Andrzej Siewior
2014-08-15 19:27 ` Sebastian Andrzej Siewior
2014-08-15 19:27 ` Sebastian Andrzej Siewior
2014-08-15 19:33 ` Lennart Sorensen
2014-08-15 19:33 ` Lennart Sorensen
2014-08-15 19:33 ` Lennart Sorensen
2014-08-15 20:20 ` Sebastian Andrzej Siewior [this message]
2014-08-15 20:20 ` Sebastian Andrzej Siewior
2014-08-15 21:07 ` Tony Lindgren
2014-08-15 21:07 ` Tony Lindgren
2014-08-15 22:44 ` Tony Lindgren
2014-08-15 22:44 ` Tony Lindgren
2014-08-29 15:49 ` Sebastian Andrzej Siewior
2014-08-29 15:49 ` Sebastian Andrzej Siewior
2014-08-29 16:08 ` Tony Lindgren
2014-08-29 16:08 ` Tony Lindgren
2014-08-21 11:00 ` Sebastian Andrzej Siewior
2014-08-21 11:00 ` Sebastian Andrzej Siewior
2014-08-21 11:00 ` Sebastian Andrzej Siewior
2014-08-21 18:38 ` Tony Lindgren
2014-08-21 18:38 ` Tony Lindgren
2014-08-18 13:46 ` Heikki Krogerus
2014-08-18 13:46 ` Heikki Krogerus
2014-09-01 13:31 ` Sebastian Andrzej Siewior
2014-09-01 13:31 ` Sebastian Andrzej Siewior
2014-09-01 13:31 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 06/15] tty: serial: 8250_dma: handle error on TX submit Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-18 13:57 ` Heikki Krogerus
2014-08-18 13:57 ` Heikki Krogerus
2014-09-01 14:38 ` Sebastian Andrzej Siewior
2014-09-01 14:38 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 07/15] tty: serial: 8250_dma: enqueue RX dma again on completion Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-18 10:52 ` One Thousand Gnomes
2014-08-18 10:52 ` One Thousand Gnomes
2014-08-29 15:52 ` Sebastian Andrzej Siewior
2014-08-29 15:52 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 08/15] dmaengine: edma: fix two faults which happen with the 8250_dma user Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 09/15] dmaengine: omap-dma: complete the transfer on terminate_all Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 10/15] tty: serial: 8250_dma: Add a TX trigger workaround for AM33xx Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 11/15] tty: serial: 8250_dma: handle the when UART response while DMA remains idle Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 12/15] tty: serial: 8250_dma: add pm runtime Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 13/15] arm: dts: am33xx: add DMA properties for UART Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 14/15] arm: dts: dra7: " Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 17:42 ` [PATCH 15/15] tty: serial: 8250: omap: add dma support Sebastian Andrzej Siewior
2014-08-15 17:42 ` Sebastian Andrzej Siewior
2014-08-15 21:02 ` Tony Lindgren
2014-08-15 21:02 ` Tony Lindgren
2014-08-21 8:34 ` Sebastian Andrzej Siewior
2014-08-21 8:34 ` Sebastian Andrzej Siewior
2014-08-21 18:44 ` Tony Lindgren
2014-08-21 18:44 ` Tony Lindgren
2014-08-27 19:54 ` Sebastian Andrzej Siewior
2014-08-27 19:54 ` Sebastian Andrzej Siewior
2014-08-27 20:23 ` Tony Lindgren
2014-08-27 20:23 ` Tony Lindgren
2014-08-28 8:23 ` Sebastian Andrzej Siewior
2014-08-28 8:23 ` Sebastian Andrzej Siewior
2014-08-28 16:46 ` Tony Lindgren
2014-08-28 16:46 ` Tony Lindgren
2014-08-28 19:37 ` Sebastian Andrzej Siewior
2014-08-28 19:37 ` Sebastian Andrzej Siewior
2014-08-28 22:54 ` Tony Lindgren
2014-08-28 22:54 ` Tony Lindgren
2014-08-29 9:32 ` Sebastian Andrzej Siewior
2014-08-29 9:32 ` Sebastian Andrzej Siewior
2014-08-29 15:55 ` Felipe Balbi
2014-08-29 15:55 ` Felipe Balbi
2014-08-29 15:55 ` Felipe Balbi
2014-08-29 16:12 ` Tony Lindgren
2014-08-29 16:12 ` Tony Lindgren
2014-08-29 16:12 ` Tony Lindgren
2014-08-29 16:31 ` Sebastian Andrzej Siewior
2014-08-29 16:31 ` Sebastian Andrzej Siewior
2014-08-29 16:31 ` Sebastian Andrzej Siewior
2014-09-01 17:47 ` Sebastian Andrzej Siewior
2014-09-01 17:47 ` Sebastian Andrzej Siewior
2014-09-02 3:05 ` Sebastian Reichel
2014-09-02 3:05 ` Sebastian Reichel
2014-09-02 16:55 ` Tony Lindgren
2014-09-02 16:55 ` Tony Lindgren
2014-09-02 18:39 ` Sebastian Andrzej Siewior
2014-09-02 18:39 ` Sebastian Andrzej Siewior
2014-09-02 20:15 ` Tony Lindgren
2014-09-02 20:15 ` Tony Lindgren
2014-09-02 20:38 ` Sebastian Reichel
2014-09-02 20:38 ` Sebastian Reichel
2014-09-03 16:46 ` Sebastian Andrzej Siewior
2014-09-03 16:46 ` Sebastian Andrzej Siewior
2014-09-03 17:48 ` Tony Lindgren
2014-09-03 17:48 ` Tony Lindgren
2014-09-04 13:44 ` Sebastian Andrzej Siewior
2014-09-04 13:44 ` Sebastian Andrzej Siewior
2014-09-04 13:44 ` Sebastian Andrzej Siewior
2014-09-04 14:52 ` Tony Lindgren
2014-09-04 14:52 ` Tony Lindgren
2014-09-04 14:52 ` Tony Lindgren
2014-09-04 14:56 ` Sebastian Andrzej Siewior
2014-09-04 14:56 ` Sebastian Andrzej Siewior
2014-09-04 14:56 ` Sebastian Andrzej Siewior
2014-09-04 16:25 ` Tony Lindgren
2014-09-04 16:25 ` Tony Lindgren
2014-09-04 16:25 ` Tony Lindgren
2014-08-15 18:17 ` [PATCH v7] 8250-core based serial driver for OMAP + DMA Lennart Sorensen
2014-08-15 18:17 ` Lennart Sorensen
2014-08-15 19:14 ` Sebastian Andrzej Siewior
2014-08-15 19:14 ` Sebastian Andrzej Siewior
2014-08-15 20:28 ` Tony Lindgren
2014-08-15 20:28 ` Tony Lindgren
2014-08-17 20:35 ` Sebastian Andrzej Siewior
2014-08-17 20:35 ` Sebastian Andrzej Siewior
2014-08-18 15:15 ` Peter Hurley
2014-08-18 15:15 ` Peter Hurley
2014-08-18 16:37 ` Felipe Balbi
2014-08-18 16:37 ` Felipe Balbi
2014-08-18 16:37 ` Felipe Balbi
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=53EE6BA5.2060101@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=balbi@ti.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=lsorense@csclub.uwaterloo.ca \
--cc=tony@atomide.com \
--cc=vinod.koul@intel.com \
/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.