linux-kernel - Re: [PATCH-V5 3/4] mfd: 88pm800: Set default interrupt clear method

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 7 Jul 2015 11:40:28 +0100
From:	Lee Jones <lee.jones@...aro.org>
To:	Vaibhav Hiremath <vaibhav.hiremath@...aro.org>
Cc:	linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
	robh+dt@...nel.org, sameo@...ux.intel.com,
	linux-kernel@...r.kernel.org, yizhang@...vell.com,
	Zhao Ye <zhaoy@...vell.com>
Subject: Re: [PATCH-V5 3/4] mfd: 88pm800: Set default interrupt clear method

On Tue, 07 Jul 2015, Vaibhav Hiremath wrote:
> On Tuesday 07 July 2015 12:59 PM, Lee Jones wrote:
> >On Mon, 29 Jun 2015, Vaibhav Hiremath wrote:
> >
> >>As per the spec, bit 1 (INT_CLEAR_MODE) of reg addr 0xe
> >>(page 0) controls the method of clearing interrupt
> >>status of 88pm800 family of devices;
> >>
> >>   0: clear on read
> >>   1: clear on write
> >>
> >>If pdata is not coming from board file, then set the
> >>default irq clear method to "irq clear on write"
> >>
> >>Also, as suggested by "Lee Jones" renaming variable field
> >>to appropriate name.
> >>
> >>Signed-off-by: Zhao Ye <zhaoy@...vell.com>
> >>Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@...aro.org>
> >>---
> >>  drivers/mfd/88pm800.c       | 15 ++++++++++-----
> >>  include/linux/mfd/88pm80x.h | 10 ++++++++--
> >>  2 files changed, 18 insertions(+), 7 deletions(-)
> >>
> >>diff --git a/drivers/mfd/88pm800.c b/drivers/mfd/88pm800.c
> >>index d495737..66347be 100644
> >>--- a/drivers/mfd/88pm800.c
> >>+++ b/drivers/mfd/88pm800.c
> >>@@ -374,7 +374,7 @@ static int device_irq_init_800(struct pm80x_chip *chip)
> >>  {
> >>  	struct regmap *map = chip->regmap;
> >>  	unsigned long flags = IRQF_ONESHOT;
> >>-	int data, mask, ret = -EINVAL;
> >>+	int irq_clr_mode, mask, ret = -EINVAL;
> >>
> >>  	if (!map || !chip->irq) {
> >>  		dev_err(chip->dev, "incorrect parameters\n");
> >>@@ -382,15 +382,16 @@ static int device_irq_init_800(struct pm80x_chip *chip)
> >>  	}
> >>
> >>  	/*
> >>-	 * irq_mode defines the way of clearing interrupt. it's read-clear by
> >>-	 * default.
> >>+	 * irq_clr_on_wr defines the way of clearing interrupt by
> >>+	 * read/write(0/1).  It's read-clear by default.
> >>  	 */
> >>  	mask =
> >>  	    PM800_WAKEUP2_INV_INT | PM800_WAKEUP2_INT_CLEAR |
> >>  	    PM800_WAKEUP2_INT_MASK;
> >>
> >>-	data = PM800_WAKEUP2_INT_CLEAR;
> >>-	ret = regmap_update_bits(map, PM800_WAKEUP2, mask, data);
> >>+	irq_clr_mode = chip->irq_clr_method == PM800_IRQ_CLR_ON_WRITE ?
> >>+		PM800_WAKEUP2_INT_WRITE_CLEAR : PM800_WAKEUP2_INT_READ_CLEAR;
> >>+	ret = regmap_update_bits(map, PM800_WAKEUP2, mask, irq_clr_mode);
> >
> >What's stopping you just passing PM800_WAKEUP2_INT_WRITE_CLEAR or
> >PM800_WAKEUP2_INT_READ_CLEAR from pdata?  Then you can use the value
> >directly without all of this faffing about.
> >
> >   regmap_update_bits(map, PM800_WAKEUP2, mask, pdata->irq_clr_mode);
> >
> 
> Because "irq_clr_method" is of boolean type.
> And macros which you are referring to is,
> 
> #define PM800_WAKEUP2_INT_READ_CLEAR            (0 << 1)
> #define PM800_WAKEUP2_INT_WRITE_CLEAR           (1 << 1)
> 
> 
> And also, I feel it is more cleaner approach with the current code as
> register definition and userflag are maintained separately.

I see your point, although it's a shame we have to have this code in
its place.

One thing I think you can do though is rid chip->irq_clr_method, just
use the one you already have in pdata.

> >>  	if (ret < 0)
> >>  		goto out;
> >>@@ -512,6 +513,7 @@ static int device_800_init(struct pm80x_chip *chip,
> >>  	}
> >>
> >>  	chip->regmap_irq_chip = &pm800_irq_chip;
> >>+	chip->irq_clr_method = pdata->irq_clr_method;
> >>
> >>  	ret = device_irq_init_800(chip);
> >>  	if (ret < 0) {
> >>@@ -564,6 +566,9 @@ static int pm800_probe(struct i2c_client *client,
> >>  		pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
> >>  		if (!pdata)
> >>  			return -ENOMEM;
> >>+
> >>+		/* by default, set irq clear method on write */
> >>+		pdata->irq_clr_method = PM800_IRQ_CLR_ON_WRITE;
> >>  	}
> >>
> >>  	ret = pm80x_init(client);
> >>diff --git a/include/linux/mfd/88pm80x.h b/include/linux/mfd/88pm80x.h
> >>index 8fcad63..648e01a 100644
> >>--- a/include/linux/mfd/88pm80x.h
> >>+++ b/include/linux/mfd/88pm80x.h
> >>@@ -77,6 +77,8 @@ enum {
> >>  #define PM800_WAKEUP2			(0x0E)
> >>  #define PM800_WAKEUP2_INV_INT		BIT(0)
> >>  #define PM800_WAKEUP2_INT_CLEAR		BIT(1)
> >>+#define PM800_WAKEUP2_INT_READ_CLEAR	(0 << 1)
> >>+#define PM800_WAKEUP2_INT_WRITE_CLEAR	(1 << 1)
> >>  #define PM800_WAKEUP2_INT_MASK		BIT(2)
> >>
> >>  #define PM800_POWER_UP_LOG		(0x10)
> >>@@ -300,7 +302,11 @@ struct pm80x_chip {
> >>  	struct regmap_irq_chip_data *irq_data;
> >>  	int type;
> >>  	int irq;
> >>-	int irq_mode;
> >>+
> >>+#define PM800_IRQ_CLR_ON_READ	0
> >>+#define PM800_IRQ_CLR_ON_WRITE	1
> >
> >Defines in the middle of structs makes for ugly code.
> >
> 
> Sorry, but kernel code is full of such implementations.
> Infact it is right place in terms of readability.
> 
> If you still feel insist to fix it, please let me know whether you want
> to submit V6 just for this. Or you will fix it while merging.
> I am OK with anything here...
> 
> 
> Thanks,
> Vaibhav

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/