From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51F81C433EF for ; Wed, 24 Nov 2021 14:47:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354348AbhKXOuV (ORCPT ); Wed, 24 Nov 2021 09:50:21 -0500 Received: from mga06.intel.com ([134.134.136.31]:42313 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354130AbhKXOuQ (ORCPT ); Wed, 24 Nov 2021 09:50:16 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10177"; a="296094983" X-IronPort-AV: E=Sophos;i="5.87,260,1631602800"; d="scan'208";a="296094983" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Nov 2021 06:47:03 -0800 X-IronPort-AV: E=Sophos;i="5.87,260,1631602800"; d="scan'208";a="475289889" Received: from smile.fi.intel.com ([10.237.72.184]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Nov 2021 06:47:02 -0800 Received: from andy by smile.fi.intel.com with local (Exim 4.95) (envelope-from ) id 1mptY2-00A8S9-NF; Wed, 24 Nov 2021 16:46:58 +0200 Date: Wed, 24 Nov 2021 16:46:58 +0200 From: Andy Shevchenko To: Bartosz Golaszewski Cc: Linus Walleij , Johan Hovold , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] gpiolib: check the 'ngpios' property in core gpiolib code Message-ID: References: <20211124122850.7095-1-brgl@bgdev.pl> <20211124122850.7095-2-brgl@bgdev.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211124122850.7095-2-brgl@bgdev.pl> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 24, 2021 at 01:28:50PM +0100, Bartosz Golaszewski wrote: > Several drivers read the 'ngpios' device property on their own, but > since it's defined as a standard GPIO property in the device tree bindings > anyway, it's a good candidate for generalization. If the driver didn't > set its gc->ngpio, try to read the 'ngpios' property from the GPIO > device's firmware node before bailing out. > Signed-off-by: Bartosz Golaszewski > Suggested-by: Andy Shevchenko > Reviewed-by: Linus Walleij > --- > v1 -> v2: > - use device_property_read_u32() instead of fwnode_property_read_u32() > - reverse the error check logic > > v2 -> v3: > - don't shadow errors other than -ENODATA in device_property_read_u32() > > drivers/gpio/gpiolib.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index ede8b8a7aa18..f79fd2551cf7 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -599,6 +599,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, > int base = gc->base; > unsigned int i; > int ret = 0; > + u32 ngpios; > > /* > * First: allocate and populate the internal stat container, and > @@ -647,9 +648,17 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, > } > if (gc->ngpio == 0) { > - chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); > - ret = -EINVAL; > - goto err_free_descs; > + ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios); > + if (ret) { > + if (ret == -ENODATA) { > + chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); > + ret = -EINVAL; > + } > + > + goto err_free_descs; > + } And if the property returns 0 in ngpios? What about the modified suggestion from previous version: if (gc->ngpio == 0) { ret = device_property_read_u32(&gdev->dev, "ngpios", &ngpios); /* * -ENODATA means that there is no property found and * we want to issue the error message to the user. Besides * that, we want to return different error code to state * that supplied value is not valid. */ if (ret == -ENODATA) ngpios = 0; else if (ret) return ret; gc->ngpio = ngpios; } if (gc->ngpio == 0) { chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); ret = -EINVAL; goto err_free_descs; } ? > + gc->ngpio = ngpios; > } > > if (gc->ngpio > FASTPATH_NGPIO) > -- > 2.25.1 > -- With Best Regards, Andy Shevchenko