From: Tony Lindgren <tony@atomide.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
balbi@ti.com, Vinod Koul <vinod.koul@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v7] 8250-core based serial driver for OMAP + DMA
Date: Fri, 15 Aug 2014 13:28:27 -0700 [thread overview]
Message-ID: <20140815202826.GC9239@atomide.com> (raw)
In-Reply-To: <53EE5BF8.3010007@linutronix.de>
* Sebastian Andrzej Siewior <bigeasy@linutronix.de> [140815 12:16]:
> On 08/15/2014 08:17 PM, Lennart Sorensen wrote:
>
> > Are you saying that with the new driver you have to respond to the RX
> > irq faster than before to avoid overflows? It is not quite clear.
>
> Yes. The irq fires 46 bytes giving you 16 bytes buffer before overflow
> vs 63 bytes buffer the old one had.
>
> > I do think 40000 interrupts to handle 40000 bytes of date does seem a
> > tad inefficient, so dropping to 854 looks a lot nicer. Was the omap
> > driver not using the fifo trigger levels at all?
>
> It configured the trigger levels to 1 for RX and 16 for TX.
Hmm that weird RX trigger level is a workaround for lost characters.
See commit 0ba5f66836 (tty: serial: OMAP: use a 1-byte RX FIFO
threshold in PIO mode :)
There's paste test in that commit, I wonder if the 8250 drivers
can deal with it any better?
Regards,
Tony
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v7] 8250-core based serial driver for OMAP + DMA
Date: Fri, 15 Aug 2014 13:28:27 -0700 [thread overview]
Message-ID: <20140815202826.GC9239@atomide.com> (raw)
In-Reply-To: <53EE5BF8.3010007@linutronix.de>
* Sebastian Andrzej Siewior <bigeasy@linutronix.de> [140815 12:16]:
> On 08/15/2014 08:17 PM, Lennart Sorensen wrote:
>
> > Are you saying that with the new driver you have to respond to the RX
> > irq faster than before to avoid overflows? It is not quite clear.
>
> Yes. The irq fires 46 bytes giving you 16 bytes buffer before overflow
> vs 63 bytes buffer the old one had.
>
> > I do think 40000 interrupts to handle 40000 bytes of date does seem a
> > tad inefficient, so dropping to 854 looks a lot nicer. Was the omap
> > driver not using the fifo trigger levels at all?
>
> It configured the trigger levels to 1 for RX and 16 for TX.
Hmm that weird RX trigger level is a workaround for lost characters.
See commit 0ba5f66836 (tty: serial: OMAP: use a 1-byte RX FIFO
threshold in PIO mode :)
There's paste test in that commit, I wonder if the 8250 drivers
can deal with it any better?
Regards,
Tony
next prev parent reply other threads:[~2014-08-15 20:28 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
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 [this message]
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
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