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From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Andres Salomon <dilinger@queued.net>
Cc: Russell King <linux@arm.linux.org.uk>,
	Samuel Ortiz <sameo@linux.intel.com>,
	Mark Brown <broonie@opensource.wolfsonmicro.com>,
	linux-kernel@vger.kernel.org, Richard Purdie <rpurdie@rpsys.net>,
	Sascha Hauer <kernel@pengutronix.de>,
	linux-arm-kernel@lists.infradead.org,
	Liam Girdwood <lrg@slimlogic.co.uk>
Subject: Re: [PATCH 15/19] mc13xxx: mfd_cell is now implicitly available to drivers
Date: Fri, 4 Feb 2011 11:13:38 +0100	[thread overview]
Message-ID: <20110204101338.GI30452@pengutronix.de> (raw)
In-Reply-To: <20110204093458.GH30452@pengutronix.de>

Hello,

On Fri, Feb 04, 2011 at 10:34:58AM +0100, Uwe Kleine-König wrote:
> And I think this patch has a conceptual problem, too.  In my opionion
> platform_data is the point to hand over platform specific data to a
> driver.  driver_data is something that is private to the driver and has
> to be considered opaque for the platform.  The driver was sort of OK
> before ...

So consequently I propose the patch below.  I'm sure that a few drivers
will break, but IMHO that's OK.

And by the way, did you know that platform_set_drvdata can fail and you
have no nice way to notice that but to do:

	dev_set_drvdata(dev, mypreciousdata);
	if (dev_get_drvdata(dev) != mypreciousdata)
		goto fail;

Best regards
Uwe

------>8-----------
From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Fri, 4 Feb 2011 11:00:42 +0100
Subject: [PATCH] MFD: platform_set_drvdata should be only called by drivers

driver data is data private to drivers so it's not a point to hand over
data to the driver by the platform.  That's what platform_data is available
for.  The only place platform_set_drvdata should be called is in a
driver that has bound the device in question.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/mfd/mfd-core.c   |    1 -
 include/linux/mfd/core.h |    3 ---
 2 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index d83ad0f..8d06e0c 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -37,7 +37,6 @@ static int mfd_add_device(struct device *parent, int id,
 		goto fail_device;
 
 	pdev->dev.parent = parent;
-	platform_set_drvdata(pdev, cell->driver_data);
 
 	if (cell->data_size) {
 		ret = platform_device_add_data(pdev,
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index 835996e..88bb7b5 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -30,9 +30,6 @@ struct mfd_cell {
 	int			(*suspend)(struct platform_device *dev);
 	int			(*resume)(struct platform_device *dev);
 
-	/* driver-specific data for MFD-aware "cell" drivers */
-	void			*driver_data;
-
 	/* platform_data can be used to either pass data to "generic"
 	   driver or as a hook to mfd_cell for the "cell" drivers */
 	void			*platform_data;
-- 
1.7.2.3

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

  reply	other threads:[~2011-02-04 10:13 UTC|newest]

Thread overview: 65+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-03  3:54 [RFC] [PATCH 0/19] mfd sharing support Andres Salomon
2011-02-03  3:55 ` [PATCH 01/19] mfd-core: unconditionally add mfd_cell to every platform_device Andres Salomon
2011-02-03  3:58 ` [PATCH 02/19] jz4740: mfd_cell is now implicitly available to drivers Andres Salomon
2011-02-03  8:09   ` Jean Delvare
2011-02-03  4:01 ` [PATCH 03/19] ab3550: " Andres Salomon
2011-02-04  8:20   ` Mattias Wallin
2011-02-03  4:03 ` [PATCH 04/19] ab3100: " Andres Salomon
2011-02-03 12:52   ` Linus Walleij
2011-02-03  4:04 ` [PATCH 05/19] asic3: " Andres Salomon
2011-02-03  4:05 ` [PATCH 06/19] htc-pasic3: " Andres Salomon
2011-02-03  4:08 ` [PATCH 07/19] timberdale: " Andres Salomon
2011-03-31 23:05   ` Grant Likely
2011-04-01 11:20     ` Samuel Ortiz
2011-04-01 17:47       ` Andres Salomon
2011-04-01 17:56         ` Grant Likely
2011-04-01 18:00           ` Grant Likely
2011-04-01 23:52           ` Samuel Ortiz
2011-04-01 23:58             ` Grant Likely
2011-04-02  0:10               ` Andres Salomon
2011-04-04 10:03               ` Samuel Ortiz
2011-04-05  3:04                 ` Grant Likely
2011-04-06 15:23                   ` Samuel Ortiz
2011-04-06 15:58                     ` Greg KH
2011-04-06 17:05                       ` Samuel Ortiz
2011-04-06 17:16                         ` Ben Hutchings
2011-04-06 17:51                           ` Samuel Ortiz
2011-04-06 18:07                             ` Ben Hutchings
2011-04-06 17:56                         ` Greg KH
2011-04-06 18:25                           ` Andres Salomon
2011-04-06 18:38                             ` Greg KH
2011-04-07  8:04                               ` Grant Likely
2011-04-06 18:47                           ` Samuel Ortiz
2011-04-06 18:59                             ` Felipe Balbi
2011-04-06 22:09                               ` Greg KH
2011-04-07  8:09                                 ` Felipe Balbi
2011-04-07 13:40                               ` Samuel Ortiz
2011-04-07 14:35                                 ` Grant Likely
2011-04-07 15:03                                   ` Samuel Ortiz
2011-04-07 18:06                                     ` Grant Likely
2011-04-07 16:24                   ` Grant Likely
2011-04-01 18:26         ` Samuel Ortiz
2011-02-03  4:09 ` [PATCH 08/19] t7166xb: " Andres Salomon
2011-02-03  4:11 ` [PATCH 09/19] wl1273: " Andres Salomon
2011-02-03  4:12 ` [PATCH 10/19] sh_mobile_sdhi: " Andres Salomon
2011-02-03  4:13 ` [PATCH 11/19] tc6393xb: " Andres Salomon
2011-02-03  4:15 ` [PATCH 12/19] twl4030: " Andres Salomon
2011-02-03  6:05   ` Dmitry Torokhov
2011-02-03  6:39     ` Andres Salomon
2011-02-03  6:53       ` Dmitry Torokhov
2011-02-03  7:03         ` Andres Salomon
2011-02-03  9:31           ` Mark Brown
2011-02-05  2:39             ` Andres Salomon
2011-02-05  3:25               ` Andres Salomon
2011-02-03 12:23           ` Peter Ujfalusi
2011-02-04 10:41           ` Uwe Kleine-König
2011-02-03  4:16 ` [PATCH 13/19] tc6387xb: " Andres Salomon
2011-02-03  4:17 ` [PATCH 14/19] janz: " Andres Salomon
2011-02-03  4:20 ` [PATCH 15/19] mc13xxx: " Andres Salomon
2011-02-04  9:34   ` Uwe Kleine-König
2011-02-04 10:13     ` Uwe Kleine-König [this message]
2011-02-04 10:16     ` Andres Salomon
2011-02-03  4:21 ` [PATCH 16/19] mfd-core: drop platform_data/data_size from core mfd_cell struct Andres Salomon
2011-02-03  4:22 ` [PATCH 17/19] mfd-core: add refcounting support to mfd_cells Andres Salomon
2011-02-03  4:23 ` [PATCH 18/19] mfd-core: add platform_device sharing support for mfd Andres Salomon
2011-02-03  4:26 ` [PATCH 19/19] cs5535-mfd: add sharing for acpi/pms cells Andres Salomon

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