From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831AbcERJDx (ORCPT ); Wed, 18 May 2016 05:03:53 -0400 Received: from mailout3.w1.samsung.com ([210.118.77.13]:12537 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751891AbcERJDt (ORCPT ); Wed, 18 May 2016 05:03:49 -0400 X-AuditID: cbfec7f4-f796c6d000001486-f7-573c2ff101c2 Message-id: <573C2FF0.3050500@samsung.com> Date: Wed, 18 May 2016 11:03:44 +0200 From: Jacek Anaszewski User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130804 Thunderbird/17.0.8 MIME-version: 1.0 To: Tony Makkiel Cc: linux-leds@vger.kernel.org, lkml , Pavel Machek , Stas Sergeev , Andrew Lunn , Sakari Ailus , =?ISO-8859-1?Q?=C1lvaro_Fern=E1ndez_Rojas?= , Dan Carpenter , Simon Guinot Subject: Re: [PATCH] Let chip-driver set brightness if, software blink not used. References: <1463502505-31799-1-git-send-email-tony.makkiel@daqri.com> In-reply-to: <1463502505-31799-1-git-send-email-tony.makkiel@daqri.com> Content-type: text/plain; charset=ISO-8859-1; format=flowed Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrDLMWRmVeSWpSXmKPExsVy+t/xy7of9W3CDWYvt7A4f/cQs8Xrf9NZ LC7vmsNmsfXNOkaLNXcOsVrcPXWUzeLTlm9MFteP7GOy6OybxmIxdcF0Rgcujz3/l7F67Jx1 l91j3slAj507PjN5fHx6i8Wj7fo8No8Vq7+zezSdamf1+LxJLoAzissmJTUnsyy1SN8ugStj 3VL3gpfaFZdOrmRuYDyl1MXIwSEhYCKx5Z10FyMnkCkmceHeerYuRi4OIYGljBK/n99hh3Ce MUp03mtlB6niFdCS+LzoHyuIzSKgKtG9ajobiM0mYCjx88VrJhBbVCBC4s/pfawQ9YISPybf YwGxRQQ0JQ61NTKCDGUW+Mok8fbxOmaQhLBAiMTGuXvAbCEBN4mnc1Ywg1zHKeAusXwiD0iY WcBaYuWkbYwQtrzE5jVvmScwCsxCsmIWkrJZSMoWMDKvYhRNLU0uKE5KzzXUK07MLS7NS9dL zs/dxAiJky87GBcfszrEKMDBqMTDu6HfOlyINbGsuDL3EKMEB7OSCK+Xrk24EG9KYmVValF+ fFFpTmrxIUZpDhYlcd65u96HCAmkJ5akZqemFqQWwWSZODilGhj5ue8tfOgT98F0dsHNu36M FjphLDbRpRfEi+ZnBmnVRux9vuKGUyyfZak8ozd/cKDhiXu7WfbMePWWy/nh/rjDgn9X1mz+ +yng8uJFuez3jfUvz5+r3jh/8v0/uSXt3hfvPloTUDfrwNY/mzdvfVfe1vAtviPlz2bPu81C GsXiHJdWXBILUVqvxFKckWioxVxUnAgAfoeGNo8CAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tony, Thanks for the patch. I'd like to improve the commit message. Please let me know if you have any suggestions related to the below: led: core: Fix brightness setting upon hardware blinking enabled Commit 76931edd54 ('leds: fix brightness changing when software blinking is active') changed the semantics of led_set_brightness() which according to the documentation should disable blinking on any brightness setting. Moreover it made it different for soft blink case, where it was allowed for blink brightness change, and for hardware blink case, where setting any brightness greater than 0 was ignored. While the change itself is against the documentation claims, it was driven also by the fact that timer trigger remained active after turning blinking off. Fixing that would have required major refactoring in the led-core, led-class, and led-triggers because of cyclic dependencies. Finally, it has been decided that allowing for brightness change during blinking is beneficial as it can be accomplished without disturbing blink rhythm. The change in brightness setting semantics will not affect existing LED class drivers that implement blink_set op thanks to the LED_BLINK_SW flag introduced by this patch. The flag state will be from now on checked in led_set_brightness() which will allow to distinguish between hardware and software blink mode. In the former case the control will be passed directly to the drivers which apply their semantics on brightness set, which is disable the blinking in case of most such drivers. New drivers will apply new semantics and just change the brightness while hardware blinking is on, if possible. Due to the later LED core improvements this patch can't be applied directly on the patch that originally introduced the problem, but to the later one, that touched the affected code. Fixes: f1e80c07416a ("leds: core: Add two new LED_BLINK_ flags") Signed-off-by: Tony Makkiel Signed-off-by: Jacek Anaszewski We will need also to modify the documentation, but this can be done in a separate patch. On 05/17/2016 06:28 PM, Tony Makkiel wrote: > With this patch, chip drivers will be given option to > set brightness while, blink is active. > > Signed-off-by: Tony Makkiel > --- > drivers/leds/led-core.c | 7 +++++-- > include/linux/leds.h | 19 ++++++++++--------- > 2 files changed, 15 insertions(+), 11 deletions(-) > > diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c > index 3495d5d..b595eb9 100644 > --- a/drivers/leds/led-core.c > +++ b/drivers/leds/led-core.c > @@ -53,11 +53,12 @@ static void led_timer_function(unsigned long data) > > if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) { > led_set_brightness_nosleep(led_cdev, LED_OFF); > + led_cdev->flags &= ~LED_BLINK_SW; > return; > } > > if (led_cdev->flags & LED_BLINK_ONESHOT_STOP) { > - led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP; > + led_cdev->flags &= ~(LED_BLINK_ONESHOT_STOP | LED_BLINK_SW); > return; > } > > @@ -151,6 +152,7 @@ static void led_set_software_blink(struct led_classdev *led_cdev, > return; > } > > + led_cdev->flags |= LED_BLINK_SW; > mod_timer(&led_cdev->blink_timer, jiffies + 1); > } > > @@ -219,6 +221,7 @@ void led_stop_software_blink(struct led_classdev *led_cdev) > del_timer_sync(&led_cdev->blink_timer); > led_cdev->blink_delay_on = 0; > led_cdev->blink_delay_off = 0; > + led_cdev->flags &= ~LED_BLINK_SW; > } > EXPORT_SYMBOL_GPL(led_stop_software_blink); > > @@ -229,7 +232,7 @@ void led_set_brightness(struct led_classdev *led_cdev, > * In case blinking is on delay brightness setting We need to make this comment more precise: s/blinking/soft blink/g > * until the next timer tick. > */ > - if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) { > + if (led_cdev->flags & LED_BLINK_SW) { > /* > * If we need to disable soft blinking delegate this to the > * work queue task to avoid problems in case we are called > diff --git a/include/linux/leds.h b/include/linux/leds.h > index d2b1306..99b1f0b 100644 > --- a/include/linux/leds.h > +++ b/include/linux/leds.h > @@ -42,15 +42,16 @@ struct led_classdev { > #define LED_UNREGISTERING (1 << 1) > /* Upper 16 bits reflect control information */ > #define LED_CORE_SUSPENDRESUME (1 << 16) > -#define LED_BLINK_ONESHOT (1 << 17) > -#define LED_BLINK_ONESHOT_STOP (1 << 18) > -#define LED_BLINK_INVERT (1 << 19) > -#define LED_BLINK_BRIGHTNESS_CHANGE (1 << 20) > -#define LED_BLINK_DISABLE (1 << 21) > -#define LED_SYSFS_DISABLE (1 << 22) > -#define LED_DEV_CAP_FLASH (1 << 23) > -#define LED_HW_PLUGGABLE (1 << 24) > -#define LED_PANIC_INDICATOR (1 << 25) > +#define LED_BLINK_SW (1 << 17) > +#define LED_BLINK_ONESHOT (1 << 18) > +#define LED_BLINK_ONESHOT_STOP (1 << 19) > +#define LED_BLINK_INVERT (1 << 20) > +#define LED_BLINK_BRIGHTNESS_CHANGE (1 << 21) > +#define LED_BLINK_DISABLE (1 << 22) > +#define LED_SYSFS_DISABLE (1 << 23) > +#define LED_DEV_CAP_FLASH (1 << 24) > +#define LED_HW_PLUGGABLE (1 << 25) > +#define LED_PANIC_INDICATOR (1 << 26) > > /* Set LED brightness level > * Must not sleep. Use brightness_set_blocking for drivers > -- Best regards, Jacek Anaszewski