From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Date: Fri, 02 Sep 2011 17:24:03 +0000 Subject: [PATCH] fb: sh-mobile: Fix deadlock risk between lock_fb_info() and Message-Id: <20110902192403.10f9cff7@neptune.home> List-Id: References: <4DF7B0B4.4060002@gmx.de> <1308337359-3480-1-git-send-email-FlorianSchandinat@gmx.de> <20110618104311.6d80ba50@neptune.home> <20110618111934.26203dbf@neptune.home> <4E5FA7F9.9030802@gmx.de> <4E61086C.3050102@gmx.de> In-Reply-To: <4E61086C.3050102@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Florian Tobias Schandinat Cc: Guennadi Liakhovetski , lethal@linux-sh.org, linux-fbdev@vger.kernel.org, francis.moro@gmail.com, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, Herton Ronaldo Krzesinski , stable@kernel.org Following on Herton's patch "fb: avoid possible deadlock caused by fb_set_suspend" which moves lock_fb_info() out of fb_set_suspend() to its callers, correct sh-mobile's locking around call to fb_set_suspend() and the same sort of deaklocks with console_lock() due to order of taking the lock. console_lock() must be taken while fb_info is already locked and fb_info must be locked while calling fb_set_suspend(). Signed-off-by: Bruno Pr=C3=A9mont Signed-off-by: Guennadi Liakhovetski --- Hi Florian, > On the other hand I just noticed the original patch didn't have > Bruno's Signed-off and a commit message was missing. So may I ask you, > Bruno, to add your Signed-off or preferably resend the version tested > by Guennadi in the appropriate patch format. Here it is with commit message and the Signed-off-by's. Thanks, Bruno drivers/video/sh_mobile_hdmi.c | 47 ++++++++++++++++++++++--------------= --- 1 files changed, 26 insertions(+), 21 deletions(-) diff --git a/drivers/video/sh_mobile_hdmi.c b/drivers/video/sh_mobile_hdmi.c index 7d54e2c..647ba98 100644 --- a/drivers/video/sh_mobile_hdmi.c +++ b/drivers/video/sh_mobile_hdmi.c @@ -1111,6 +1111,7 @@ static long sh_hdmi_clk_configure(struct sh_hdmi *hdm= i, unsigned long hdmi_rate, static void sh_hdmi_edid_work_fn(struct work_struct *work) { struct sh_hdmi *hdmi =3D container_of(work, struct sh_hdmi, edid_work.wor= k); + struct fb_info *info; struct sh_mobile_hdmi_info *pdata =3D hdmi->dev->platform_data; struct sh_mobile_lcdc_chan *ch; int ret; @@ -1123,8 +1124,9 @@ static void sh_hdmi_edid_work_fn(struct work_struct *= work) =20 mutex_lock(&hdmi->mutex); =20 + info =3D hdmi->info; + if (hdmi->hp_state =3D HDMI_HOTPLUG_CONNECTED) { - struct fb_info *info =3D hdmi->info; unsigned long parent_rate =3D 0, hdmi_rate; =20 ret =3D sh_hdmi_read_edid(hdmi, &hdmi_rate, &parent_rate); @@ -1148,42 +1150,45 @@ static void sh_hdmi_edid_work_fn(struct work_struct= *work) =20 ch =3D info->par; =20 - console_lock(); + if (lock_fb_info(info)) { + console_lock(); =20 - /* HDMI plug in */ - if (!sh_hdmi_must_reconfigure(hdmi) && - info->state =3D FBINFO_STATE_RUNNING) { - /* - * First activation with the default monitor - just turn - * on, if we run a resume here, the logo disappears - */ - if (lock_fb_info(info)) { + /* HDMI plug in */ + if (!sh_hdmi_must_reconfigure(hdmi) && + info->state =3D FBINFO_STATE_RUNNING) { + /* + * First activation with the default monitor - just turn + * on, if we run a resume here, the logo disappears + */ info->var.width =3D hdmi->var.width; info->var.height =3D hdmi->var.height; sh_hdmi_display_on(hdmi, info); - unlock_fb_info(info); + } else { + /* New monitor or have to wake up */ + fb_set_suspend(info, 0); } - } else { - /* New monitor or have to wake up */ - fb_set_suspend(info, 0); - } =20 - console_unlock(); + console_unlock(); + unlock_fb_info(info); + } } else { ret =3D 0; - if (!hdmi->info) + if (!info) goto out; =20 hdmi->monspec.modedb_len =3D 0; fb_destroy_modedb(hdmi->monspec.modedb); hdmi->monspec.modedb =3D NULL; =20 - console_lock(); + if (lock_fb_info(info)) { + console_lock(); =20 - /* HDMI disconnect */ - fb_set_suspend(hdmi->info, 1); + /* HDMI disconnect */ + fb_set_suspend(info, 1); =20 - console_unlock(); + console_unlock(); + unlock_fb_info(info); + } } =20 out: