From patchwork Fri Aug 1 11:27:54 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dexuan Cui X-Patchwork-Id: 4662241 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id DCAC09F319 for ; Fri, 1 Aug 2014 10:26:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ED5802020A for ; Fri, 1 Aug 2014 10:26:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02B7A20200 for ; Fri, 1 Aug 2014 10:26:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754024AbaHAK0F (ORCPT ); Fri, 1 Aug 2014 06:26:05 -0400 Received: from p3plsmtps2ded01.prod.phx3.secureserver.net ([208.109.80.58]:48430 "EHLO p3plsmtps2ded01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752946AbaHAK0E (ORCPT ); Fri, 1 Aug 2014 06:26:04 -0400 Received: from linuxonhyperv.com ([72.167.245.219]) by p3plsmtps2ded01.prod.phx3.secureserver.net with : DED : id ZNS21o01F4kklxU01NS20c; Fri, 01 Aug 2014 03:26:03 -0700 x-originating-ip: 72.167.245.219 Received: by linuxonhyperv.com (Postfix, from userid 518) id 55F05190879; Fri, 1 Aug 2014 04:27:54 -0700 (PDT) From: Dexuan Cui To: gregkh@linuxfoundation.org, tomi.valkeinen@ti.com, plagnioj@jcrosoft.com, dan.carpenter@oracle.com, linux-kernel@vger.kernel.org, driverdev-devel@linuxdriverproject.org, linux-fbdev@vger.kernel.org Cc: olaf@aepfle.de, apw@canonical.com, jasowang@redhat.com, kys@microsoft.com, haiyangz@microsoft.com Subject: [PATCH v4] video: hyperv: hyperv_fb: refresh the VM screen by force on VM panic Date: Fri, 1 Aug 2014 04:27:54 -0700 Message-Id: <1406892474-6548-1-git-send-email-decui@microsoft.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently the VSC has no chance to notify the VSP of the dirty rectangle on VM panic because the notification work is done in a workqueue, and in panic() the kernel typically ends up in an infinite loop, and a typical kernel config has CONFIG_PREEMPT_VOLUNTARY=y and CONFIG_PREEMPT is not set, so a context switch can't happen in panic() and the workqueue won't have a chance to run. As a result, the VM Connection window can't refresh until it's closed and we re-connect to the VM. We can register a handler on panic_notifier_list: the handler can notify the VSC and switch the framebuffer driver to a "synchronous mode", meaning the VSC flushes any future framebuffer change to the VSP immediately. v2: removed the MS-TFS line in the commit message v3: remove some 'unlikely' markings v4: avoid global variables as Tomi Valkeinen suggested Cc: Haiyang Zhang Signed-off-by: Dexuan Cui --- drivers/video/fbdev/hyperv_fb.c | 62 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 59 insertions(+), 3 deletions(-) diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index e23392e..569e756 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -224,6 +224,11 @@ struct hvfb_par { u32 pseudo_palette[16]; u8 init_buf[MAX_VMBUS_PKT_SIZE]; u8 recv_buf[MAX_VMBUS_PKT_SIZE]; + + /* If true, the VSC notifies the VSP on every framebuffer change */ + bool synchronous_fb; + + struct notifier_block hvfb_panic_nb; }; static uint screen_width = HVFB_WIDTH; @@ -532,6 +537,19 @@ static void hvfb_update_work(struct work_struct *w) schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY); } +static int hvfb_on_panic(struct notifier_block *nb, + unsigned long e, void *p) +{ + struct hvfb_par *par; + struct fb_info *info; + + par = container_of(nb, struct hvfb_par, hvfb_panic_nb); + par->synchronous_fb = true; + info = par->info; + synthvid_update(info); + + return NOTIFY_DONE; +} /* Framebuffer operation handlers */ @@ -582,14 +600,44 @@ static int hvfb_blank(int blank, struct fb_info *info) return 1; /* get fb_blank to set the colormap to all black */ } +static void hvfb_cfb_fillrect(struct fb_info *p, + const struct fb_fillrect *rect) +{ + struct hvfb_par *par = p->par; + + cfb_fillrect(p, rect); + if (par->synchronous_fb) + synthvid_update(p); +} + +static void hvfb_cfb_copyarea(struct fb_info *p, + const struct fb_copyarea *area) +{ + struct hvfb_par *par = p->par; + + cfb_copyarea(p, area); + if (par->synchronous_fb) + synthvid_update(p); +} + +static void hvfb_cfb_imageblit(struct fb_info *p, + const struct fb_image *image) +{ + struct hvfb_par *par = p->par; + + cfb_imageblit(p, image); + if (par->synchronous_fb) + synthvid_update(p); +} + static struct fb_ops hvfb_ops = { .owner = THIS_MODULE, .fb_check_var = hvfb_check_var, .fb_set_par = hvfb_set_par, .fb_setcolreg = hvfb_setcolreg, - .fb_fillrect = cfb_fillrect, - .fb_copyarea = cfb_copyarea, - .fb_imageblit = cfb_imageblit, + .fb_fillrect = hvfb_cfb_fillrect, + .fb_copyarea = hvfb_cfb_copyarea, + .fb_imageblit = hvfb_cfb_imageblit, .fb_blank = hvfb_blank, }; @@ -801,6 +849,11 @@ static int hvfb_probe(struct hv_device *hdev, par->fb_ready = true; + par->synchronous_fb = false; + par->hvfb_panic_nb.notifier_call = hvfb_on_panic; + atomic_notifier_chain_register(&panic_notifier_list, + &par->hvfb_panic_nb); + return 0; error: @@ -820,6 +873,9 @@ static int hvfb_remove(struct hv_device *hdev) struct fb_info *info = hv_get_drvdata(hdev); struct hvfb_par *par = info->par; + atomic_notifier_chain_unregister(&panic_notifier_list, + &par->hvfb_panic_nb); + par->update = false; par->fb_ready = false;