From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6FBF11DF98E; Wed, 19 Mar 2025 14:36:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742395015; cv=none; b=MvUymwecgI2X71Ze9IIsZiNsxdtwRehdSJjnyb9gnHEW17lH58U46fpqoSqO3DbYfBDIQc0OqG98Prlf8L/BzSzhUhptYdQJJbfsnc+2e3utZVd75lQHiwTKolPdGM6HmEN8egRq3eouATARkXYJU2qUgYuzPuQNOBwQ1gklAwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742395015; c=relaxed/simple; bh=V3BtB8bS98KBqj1dEkfRvbBBA7ynGH/2CaGOufpwrjk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y+78raCHs/uSYZct6pn1vGwvGozlOPYvFW4Pl0WXBw8LaifnzXMIC6+1ZrOR4IKvSJ6+8CXzTnUaejSOsh1hxE+vQJXZe6hV5b9X1J7Yw2VNNjXXlJC0L3t+pg0adOfoSLvzwZPT/u6hbypIpp0H+AGccfo+FmPi1B7vA8ZhTTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aTIgvVoE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="aTIgvVoE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43F60C4CEE8; Wed, 19 Mar 2025 14:36:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1742395015; bh=V3BtB8bS98KBqj1dEkfRvbBBA7ynGH/2CaGOufpwrjk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aTIgvVoE6EdFyZSi15qZUYmb3E1fghDxTqq14veFfH9Nk/cDgMktILavjxpVIOU+N +kIf+jp0njoLBRctbBNgkrs+pVAuGXbCYhEY9RC3UytfkugctBWDr4pP5/iAJBiP4j oILLU7iz5fwofI8OozSy+jCS0JYVNr2ZHKuAt20w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Saurabh Sengar , Michael Kelley , Wei Liu , Sasha Levin Subject: [PATCH 6.12 027/231] fbdev: hyperv_fb: Allow graceful removal of framebuffer Date: Wed, 19 Mar 2025 07:28:40 -0700 Message-ID: <20250319143027.494134892@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250319143026.865956961@linuxfoundation.org> References: <20250319143026.865956961@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Saurabh Sengar [ Upstream commit ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb ] 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 Reviewed-by: Michael Kelley Tested-by: Michael Kelley Link: https://lore.kernel.org/r/1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu Message-ID: <1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com> Signed-off-by: Sasha Levin --- 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 9798a34ac571f..75338ffc703fb 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=" */ @@ -1178,7 +1192,7 @@ 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; @@ -1226,14 +1240,10 @@ 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) -- 2.39.5