From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752692Ab2JHNgH (ORCPT ); Mon, 8 Oct 2012 09:36:07 -0400 Received: from db3ehsobe005.messaging.microsoft.com ([213.199.154.143]:11430 "EHLO db3outboundpool.messaging.microsoft.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752239Ab2JHNgF (ORCPT ); Mon, 8 Oct 2012 09:36:05 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzzz1202h1d1ah1d2ahzz8275bhz2dh2a8h668h839hd24he5bhf0ah107ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1155h) From: Fabio Estevam To: CC: , , , Fabio Estevam Subject: [PATCH] video: imxfb: Do not crash on reboot Date: Mon, 8 Oct 2012 10:35:36 -0300 Message-ID: <1349703336-8105-1-git-send-email-fabio.estevam@freescale.com> X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Issuing a "reboot" command after the LCD times out causes the following warnings: Requesting system reboot ------------[ cut here ]------------ WARNING: at drivers/clk/clk.c:471 clk_disable+0x24/0x50() Modules linked in: [] (unwind_backtrace+0x0/0xf4) from [] (warn_slowpath_common+0x48/0x60) [] (warn_slowpath_common+0x48/0x60) from [] (warn_slowpath_null+0x1c/0x24) [] (warn_slowpath_null+0x1c/0x24) from [] (clk_disable+0x24/0x50) [] (clk_disable+0x24/0x50) from [] (imxfb_disable_controller+0x48/0x7c) [] (imxfb_disable_controller+0x48/0x7c) from [] (platform_drv_shutdown+0x18/0x1c) [] (platform_drv_shutdown+0x18/0x1c) from [] (device_shutdown+0x48/0x14c) [] (device_shutdown+0x48/0x14c) from [] (kernel_restart_prepare+0x2c/0x3c) [] (kernel_restart_prepare+0x2c/0x3c) from [] (kernel_restart+0xc/0x48) [] (kernel_restart+0xc/0x48) from [] (sys_reboot+0xc0/0x1bc) [] (sys_reboot+0xc0/0x1bc) from [] (ret_fast_syscall+0x0/0x2c) ---[ end trace da6b502ca79c854f ]--- ------------[ cut here ]------------ WARNING: at drivers/clk/clk.c:380 clk_unprepare+0x1c/0x2c() Modules linked in: [] (unwind_backtrace+0x0/0xf4) from [] (warn_slowpath_common+0x48/0x60) [] (warn_slowpath_common+0x48/0x60) from [] (warn_slowpath_null+0x1c/0x24) [] (warn_slowpath_null+0x1c/0x24) from [] (clk_unprepare+0x1c/0x2c) [] (clk_unprepare+0x1c/0x2c) from [] (imxfb_disable_controller+0x50/0x7c) [] (imxfb_disable_controller+0x50/0x7c) from [] (platform_drv_shutdown+0x18/0x1c) [] (platform_drv_shutdown+0x18/0x1c) from [] (device_shutdown+0x48/0x14c) [] (device_shutdown+0x48/0x14c) from [] (kernel_restart_prepare+0x2c/0x3c) [] (kernel_restart_prepare+0x2c/0x3c) from [] (kernel_restart+0xc/0x48) [] (kernel_restart+0xc/0x48) from [] (sys_reboot+0xc0/0x1bc) [] (sys_reboot+0xc0/0x1bc) from [] (ret_fast_syscall+0x0/0x2c) ---[ end trace da6b502ca79c8550 ]--- ------------[ cut here ]------------ This happens because "reboot" triggers imxfb_shutdown(), which calls imxfb_disable_controller with the clocks already disabled. To prevent this, add a clock enabled status so that we can check if the clocks are enabled before disabling them. Signed-off-by: Fabio Estevam --- drivers/video/imxfb.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c index f3363b2..6acf98a 100644 --- a/drivers/video/imxfb.c +++ b/drivers/video/imxfb.c @@ -134,6 +134,7 @@ struct imxfb_info { struct clk *clk_ipg; struct clk *clk_ahb; struct clk *clk_per; + int enabled; /* * These are the addresses we mapped @@ -530,9 +531,12 @@ static void imxfb_enable_controller(struct imxfb_info *fbi) */ writel(RMCR_LCDC_EN_MX1, fbi->regs + LCDC_RMCR); - clk_prepare_enable(fbi->clk_ipg); - clk_prepare_enable(fbi->clk_ahb); - clk_prepare_enable(fbi->clk_per); + if (!fbi->enabled) { + clk_prepare_enable(fbi->clk_ipg); + clk_prepare_enable(fbi->clk_ahb); + clk_prepare_enable(fbi->clk_per); + fbi->enabled = 1; + } if (fbi->backlight_power) fbi->backlight_power(1); @@ -551,9 +555,12 @@ static void imxfb_disable_controller(struct imxfb_info *fbi) writel(0, fbi->regs + LCDC_RMCR); - clk_disable_unprepare(fbi->clk_per); - clk_disable_unprepare(fbi->clk_ipg); - clk_disable_unprepare(fbi->clk_ahb); + if (fbi->enabled) { + clk_disable_unprepare(fbi->clk_per); + clk_disable_unprepare(fbi->clk_ipg); + clk_disable_unprepare(fbi->clk_ahb); + fbi->enabled = 0; + } } static int imxfb_blank(int blank, struct fb_info *info) -- 1.7.9.5