From patchwork Sat Mar 1 16:16:31 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Saurabh Sengar X-Patchwork-Id: 869750 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9EA6E1D90B3; Sat, 1 Mar 2025 16:16:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740845801; cv=none; b=DZhxPSCLTMiqZ0ZbnkiQ71drSVdqJw9BWJXZ6aNuztHXX805BiwfLwY8n/phnl+scCZIvr38KQMoXIQQdoJZvALuYRyl+ddGtq58eaKuiGA6Oe5BX6yBShD9wN6qmwpAiDG4SN8UJh49CvXMNfda1DOHEnRJTwjkELurXoDlt9E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740845801; c=relaxed/simple; bh=ThW6x6jEbi3YwvsTGyO9W7L6HPAXyomQaT9YP7neygM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=KrjkUy2w1w8OAkcYkxmQmYZRbsMyxRlXtJYWMdp67VRX2Jv7jqgr8YhbNN2PnurLuI6g5dipPCMBdp7QB79vkzCDsq6wz+vY67VpHihkOSeAfTH22DXm6I8ZuPTpxRLxuY/eGZ82RnN4OeOFECRPNogE8yAJTWzCYUIKDy/DLaA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=hadrIRIn; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="hadrIRIn" Received: from linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net (linux.microsoft.com [13.77.154.182]) by linux.microsoft.com (Postfix) with ESMTPSA id 1C4E72038A40; Sat, 1 Mar 2025 08:16:39 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 1C4E72038A40 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1740845799; bh=8gqAcMLnchdt5cB0aO9gsMnZQpWztt0YAxo1ANaGVKM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hadrIRIn2gZ30Xw12Fa87w8bx4DQEfoRmfgICzUQYqP9zX4vdO9IhVDkXKnilYRBE EI/B/wuXhZTdzADIPNIAb8ANnWYE5g2e2PN+eg/7JqWTTSm/yVSjmGjq7f2gZB1uUp +WZ13FEXqGGxHhNjEC/t8+aKNYcLksQJAMHUcTME= From: Saurabh Sengar To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, deller@gmx.de, akpm@linux-foundation.org, linux-hyperv@vger.kernel.org, linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: ssengar@microsoft.com, mhklinux@outlook.com Subject: [PATCH v3 2/2] fbdev: hyperv_fb: Allow graceful removal of framebuffer Date: Sat, 1 Mar 2025 08:16:31 -0800 Message-Id: <1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1740845791-19977-1-git-send-email-ssengar@linux.microsoft.com> References: <1740845791-19977-1-git-send-email-ssengar@linux.microsoft.com> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to release the framebuffer forcefully. If this framebuffer is in use it produce the following WARN and hence this framebuffer is never released. [ 44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40 < snip > [ 44.111289] Call Trace: [ 44.111290] [ 44.111291] ? show_regs+0x6c/0x80 [ 44.111295] ? __warn+0x8d/0x150 [ 44.111298] ? framebuffer_release+0x2c/0x40 [ 44.111300] ? report_bug+0x182/0x1b0 [ 44.111303] ? handle_bug+0x6e/0xb0 [ 44.111306] ? exc_invalid_op+0x18/0x80 [ 44.111308] ? asm_exc_invalid_op+0x1b/0x20 [ 44.111311] ? framebuffer_release+0x2c/0x40 [ 44.111313] ? hvfb_remove+0x86/0xa0 [hyperv_fb] [ 44.111315] vmbus_remove+0x24/0x40 [hv_vmbus] [ 44.111323] device_remove+0x40/0x80 [ 44.111325] device_release_driver_internal+0x20b/0x270 [ 44.111327] ? bus_find_device+0xb3/0xf0 Fix this by moving the release of framebuffer and assosiated memory to fb_ops.fb_destroy function, so that framebuffer framework handles it gracefully. While we fix this, also replace manual registrations/unregistration of framebuffer with devm_register_framebuffer. Fixes: 68a2d20b79b1 ("drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver") Signed-off-by: Saurabh Sengar --- [V3] - using simplified hvfb_putmem() drivers/video/fbdev/hyperv_fb.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index 09fb025477f7..76a42379c8df 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -282,6 +282,8 @@ static uint screen_depth; static uint screen_fb_size; static uint dio_fb_size; /* FB size for deferred IO */ +static void hvfb_putmem(struct fb_info *info); + /* Send message to Hyper-V host */ static inline int synthvid_send(struct hv_device *hdev, struct synthvid_msg *msg) @@ -862,6 +864,17 @@ static void hvfb_ops_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, hvfb_ondemand_refresh_throttle(par, x, y, width, height); } +/* + * fb_ops.fb_destroy is called by the last put_fb_info() call at the end + * of unregister_framebuffer() or fb_release(). Do any cleanup related to + * framebuffer here. + */ +static void hvfb_destroy(struct fb_info *info) +{ + hvfb_putmem(info); + framebuffer_release(info); +} + /* * TODO: GEN1 codepaths allocate from system or DMA-able memory. Fix the * driver to use the _SYSMEM_ or _DMAMEM_ helpers in these cases. @@ -877,6 +890,7 @@ static const struct fb_ops hvfb_ops = { .fb_set_par = hvfb_set_par, .fb_setcolreg = hvfb_setcolreg, .fb_blank = hvfb_blank, + .fb_destroy = hvfb_destroy, }; /* Get options from kernel paramenter "video=" */ @@ -1172,7 +1186,7 @@ static int hvfb_probe(struct hv_device *hdev, if (ret) goto error; - ret = register_framebuffer(info); + ret = devm_register_framebuffer(&hdev->device, info); if (ret) { pr_err("Unable to register framebuffer\n"); goto error; @@ -1220,14 +1234,10 @@ static void hvfb_remove(struct hv_device *hdev) fb_deferred_io_cleanup(info); - unregister_framebuffer(info); cancel_delayed_work_sync(&par->dwork); vmbus_close(hdev->channel); hv_set_drvdata(hdev, NULL); - - hvfb_putmem(info); - framebuffer_release(info); } static int hvfb_suspend(struct hv_device *hdev)