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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E00FAC25B10 for ; Fri, 10 May 2024 12:05:56 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2FE9710E128; Fri, 10 May 2024 12:05:56 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="aI4kyUx+"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4837310E128 for ; Fri, 10 May 2024 12:05:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1715342754; x=1746878754; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=rzaMEotraMZU3G4QSPccOjV7Z6nrXVR+82iLRVC2MyI=; b=aI4kyUx+F5TS5qOLCXEWBiRlWD3T0wwLZ5RNtZXHsGKI+Md6lp/usezn jDMJR9aSy6eP5ENMpm1DPWyfVTpzYhHlaSDO8JloNFOnbZmuD1pYssSY4 2FLKRCwOkTCHE+/zOsEexKAOkjN4CydMlobDpMU06ltQITT6evUJWOc6y lobpGiZShEc0OcxWSopxW2pfod91Y5OglaiH1qA+lK1JvWMtSq3avjEyq id3WzHEm6KyL28Q2gbxYSvGvxIlCAzZ2l+FhTHdrGoQPS4IunZRRa+kx4 COE+omg8UJcMvJmN2vrxxMmdSjWib6fn7ie2tRRZo1yO73TVfV8204tPW Q==; X-CSE-ConnectionGUID: UrtPHf+gSv+yvpm1ryMwqw== X-CSE-MsgGUID: e9yJg1LfRduL5nPhBty1gA== X-IronPort-AV: E=McAfee;i="6600,9927,11068"; a="33831947" X-IronPort-AV: E=Sophos;i="6.08,151,1712646000"; d="scan'208";a="33831947" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2024 05:05:39 -0700 X-CSE-ConnectionGUID: V4mfCCWnR3u+qbZaYtf8Sg== X-CSE-MsgGUID: XXH/ogSXRDiZ5UBlxPD/OQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,151,1712646000"; d="scan'208";a="29657353" Received: from ettammin-desk.ger.corp.intel.com (HELO localhost) ([10.245.246.180]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 May 2024 05:05:36 -0700 From: Jani Nikula To: Thomas Zimmermann , javierm@redhat.com, airlied@redhat.com, sean@poorly.run Cc: dri-devel@lists.freedesktop.org, Thomas Zimmermann Subject: Re: [PATCH v2 2/5] drm/udl: Move drm_dev_{enter,exit}() into udl_get_edid_block() In-Reply-To: <20240410120928.26487-3-tzimmermann@suse.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20240410120928.26487-1-tzimmermann@suse.de> <20240410120928.26487-3-tzimmermann@suse.de> Date: Fri, 10 May 2024 15:05:32 +0300 Message-ID: <871q69j2ib.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, 10 Apr 2024, Thomas Zimmermann wrote: > Protect the code in udl_get_edid_block() with drm_dev_enter() and > drm_dev_exit(), so that all callers automatically invoke it. The > function uses hardware resources, which can be hot-unplugged at > any time. The other code in udl_connector_detect() does not use the > resources of the hardware device and therefore does not require > protection. > > This change will allow to use udl_get_edid_block() in various > contexts easily. > > Signed-off-by: Thomas Zimmermann Reviewed-by: Jani Nikula > --- > drivers/gpu/drm/udl/udl_modeset.c | 20 +++++++++++--------- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c > index 751da3a294c44..3df9fc38388b4 100644 > --- a/drivers/gpu/drm/udl/udl_modeset.c > +++ b/drivers/gpu/drm/udl/udl_modeset.c > @@ -434,13 +434,18 @@ static int udl_get_edid_block(void *data, u8 *buf, unsigned int block, size_t le > struct drm_device *dev = &udl->drm; > struct usb_device *udev = udl_to_usb_device(udl); > u8 *read_buff; > - int ret; > + int idx, ret; > size_t i; > > read_buff = kmalloc(2, GFP_KERNEL); > if (!read_buff) > return -ENOMEM; > > + if (!drm_dev_enter(dev, &idx)) { > + ret = -ENODEV; > + goto err_kfree; > + } > + > for (i = 0; i < len; i++) { > int bval = (i + block * EDID_LENGTH) << 8; > > @@ -449,20 +454,23 @@ static int udl_get_edid_block(void *data, u8 *buf, unsigned int block, size_t le > 0xA1, read_buff, 2, USB_CTRL_GET_TIMEOUT); > if (ret < 0) { > drm_err(dev, "Read EDID byte %zu failed err %x\n", i, ret); > - goto err_kfree; > + goto err_drm_dev_exit; > } else if (ret < 1) { > ret = -EIO; > drm_err(dev, "Read EDID byte %zu failed\n", i); > - goto err_kfree; > + goto err_drm_dev_exit; > } > > buf[i] = read_buff[1]; > } > > + drm_dev_exit(idx); > kfree(read_buff); > > return 0; > > +err_drm_dev_exit: > + drm_dev_exit(idx); > err_kfree: > kfree(read_buff); > return ret; > @@ -474,21 +482,15 @@ static enum drm_connector_status udl_connector_detect(struct drm_connector *conn > struct udl_device *udl = to_udl(dev); > struct udl_connector *udl_connector = to_udl_connector(connector); > enum drm_connector_status status = connector_status_disconnected; > - int idx; > > /* cleanup previous EDID */ > kfree(udl_connector->edid); > udl_connector->edid = NULL; > > - if (!drm_dev_enter(dev, &idx)) > - return connector_status_disconnected; > - > udl_connector->edid = drm_do_get_edid(connector, udl_get_edid_block, udl); > if (udl_connector->edid) > status = connector_status_connected; > > - drm_dev_exit(idx); > - > return status; > } -- Jani Nikula, Intel