From: Peter Rosin <peda@axentia.se>
To: Nicolas Ferre <nicolas.ferre@microchip.com>,
linux-kernel@vger.kernel.org,
Boris Brezillon <boris.brezillon@bootlin.com>
Cc: "wenyouya@gmail.com" <wenyouya@gmail.com>,
Josh Wu <rainyfeeling@outlook.com>,
Richard Weinberger <richard@nod.at>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Marek Vasut <marek.vasut@gmail.com>,
Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
linux-mtd@lists.infradead.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma
Date: Thu, 29 Mar 2018 16:23:32 +0200 [thread overview]
Message-ID: <12f7f95a-0e1d-14d0-b402-10d1172004b3@axentia.se> (raw)
In-Reply-To: <30d8bd45-4e5d-3703-5f41-07f5fc70f09d@microchip.com>
On 2018-03-29 16:20, Nicolas Ferre wrote:
> On 29/03/2018 at 15:10, Peter Rosin wrote:
>> On a sama5d31 with a Full-HD dual LVDS panel (132MHz pixel clock) NAND
>> flash accesses have a tendency to cause display disturbances. Add a
>> module param to disable DMA from the NAND controller, since that fixes
>> the display problem for me.
>>
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>> drivers/mtd/nand/raw/atmel/nand-controller.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
>> index b2f00b398490..2ff7a77c7b8e 100644
>> --- a/drivers/mtd/nand/raw/atmel/nand-controller.c
>> +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
>> @@ -129,6 +129,11 @@
>> #define DEFAULT_TIMEOUT_MS 1000
>> #define MIN_DMA_LEN 128
>>
>> +static bool atmel_nand_avoid_dma __read_mostly;
>> +
>> +MODULE_PARM_DESC(avoiddma, "Avoid using DMA");
>> +module_param_named(avoiddma, atmel_nand_avoid_dma, bool, 0400);
>
> We had the DT parameter "atmel,nand-has-dma" for this purpose and it was
> associated with a module parameter as well (use_dma,).
>
> Is it only managed by old DT binding?
Saw it, but I need the reverse. I.e. *not* using DMA.
And I didn't think this belonged in DT since in some sense it doesn't really
describe HW so I went with a module parameter.
Cheers,
Peter
next prev parent reply other threads:[~2018-03-29 14:23 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-29 13:10 [PATCH] mtd: nand: raw: atmel: add module param to avoid using dma Peter Rosin
2018-03-29 13:33 ` Boris Brezillon
2018-03-29 13:37 ` Peter Rosin
2018-03-29 13:44 ` Boris Brezillon
2018-03-29 14:27 ` Peter Rosin
2018-03-30 21:43 ` Peter Rosin
2018-04-02 12:22 ` Boris Brezillon
2018-04-02 17:59 ` Peter Rosin
2018-04-02 19:28 ` Boris Brezillon
2018-04-02 20:20 ` Boris Brezillon
2018-04-02 20:32 ` Boris Brezillon
2018-04-03 6:11 ` Peter Rosin
2018-04-03 7:18 ` Boris Brezillon
2018-04-11 14:44 ` Peter Rosin
2018-04-11 14:59 ` Boris Brezillon
2018-04-11 15:10 ` Peter Rosin
2018-04-11 15:34 ` Boris Brezillon
2018-04-11 15:34 ` Nicolas Ferre
2018-04-12 7:18 ` Peter Rosin
2018-05-22 18:03 ` Peter Rosin
2018-05-23 10:42 ` Boris Brezillon
2018-05-25 14:51 ` Tudor Ambarus
2018-05-26 17:40 ` Peter Rosin
2018-05-27 9:18 ` Peter Rosin
2018-05-27 22:11 ` Peter Rosin
2018-05-28 10:10 ` Peter Rosin
2018-05-28 14:27 ` Boris Brezillon
2018-05-28 15:52 ` Peter Rosin
2018-05-28 16:09 ` Boris Brezillon
2018-05-28 16:09 ` Nicolas Ferre
2018-05-29 6:30 ` Eugen Hristev
2018-05-29 7:10 ` Peter Rosin
2018-05-29 7:25 ` Eugen Hristev
2018-05-29 14:49 ` Boris Brezillon
2018-05-29 15:01 ` Eugen Hristev
2018-05-29 15:15 ` Boris Brezillon
2018-05-29 15:21 ` Eugen Hristev
2018-05-29 15:46 ` Boris Brezillon
2018-05-29 17:57 ` Boris Brezillon
2018-05-29 21:37 ` Peter Rosin
2018-06-04 15:46 ` Tudor Ambarus
2018-06-04 16:03 ` Boris Brezillon
2018-04-03 6:51 ` Peter Rosin
2018-04-03 7:15 ` Boris Brezillon
2018-04-03 7:32 ` Boris Brezillon
2018-04-03 8:14 ` Peter Rosin
2018-04-03 8:30 ` Boris Brezillon
2018-04-02 20:23 ` Peter Rosin
2018-04-02 20:35 ` Boris Brezillon
2018-04-03 7:18 ` Alexandre Belloni
2018-04-03 8:37 ` Peter Rosin
2018-03-29 14:20 ` Nicolas Ferre
2018-03-29 14:23 ` Peter Rosin [this message]
2018-03-29 14:29 ` Boris Brezillon
2018-06-18 8:39 ` Boris Brezillon
2018-06-18 14:00 ` Miquel Raynal
2018-06-25 12:31 ` Miquel Raynal
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