From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752563AbdF2LZz (ORCPT ); Thu, 29 Jun 2017 07:25:55 -0400 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:33183 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751848AbdF2LZu (ORCPT ); Thu, 29 Jun 2017 07:25:50 -0400 X-ME-Sender: X-Sasl-enc: 46AJItSxeQArmiC0bM59aAPj48ehdnhy9lfOawJNuPDi 1498735548 From: Dhananjay Balan To: sudipm.mukherjee@gmail.com Cc: teddy.wang@siliconmotion.com, gregkh@linuxfoundation.org, linux-fbdev@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, Dhananjay Balan Subject: [PATCH] drivers: staging: sm750: Hold lock irrespective of fb numbers. Date: Thu, 29 Jun 2017 13:24:35 +0200 Message-Id: <20170629112435.30376-1-mail@dbalan.in> X-Mailer: git-send-email 2.13.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Start holding the lock for all cases irrespective of number of fb, there could be a deadlock since this number could change in the lifetime of this lock Signed-off-by: Dhananjay Balan --- drivers/staging/sm750fb/sm750.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index d5934f372387..af5c3c93a077 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -183,19 +183,19 @@ static void lynxfb_ops_fillrect(struct fb_info *info, rop = (region->rop != ROP_COPY) ? HW_ROP2_XOR : HW_ROP2_COPY; /* - * If not use spin_lock,system will die if user load driver + * If not use spin_lock, system will die if user load driver * and immediately unload driver frequently (dual) + * since they fb_count could change during the lifetime of + * this lock, we are holding it for all cases. */ - if (sm750_dev->fb_count > 1) - spin_lock(&sm750_dev->slock); + spin_lock(&sm750_dev->slock); sm750_dev->accel.de_fillrect(&sm750_dev->accel, base, pitch, Bpp, region->dx, region->dy, region->width, region->height, color, rop); - if (sm750_dev->fb_count > 1) - spin_unlock(&sm750_dev->slock); + spin_unlock(&sm750_dev->slock); } static void lynxfb_ops_copyarea(struct fb_info *info, @@ -219,17 +219,17 @@ static void lynxfb_ops_copyarea(struct fb_info *info, /* * If not use spin_lock, system will die if user load driver * and immediately unload driver frequently (dual) + * since they fb_count could change during the lifetime of + * this lock, we are holding it for all cases. */ - if (sm750_dev->fb_count > 1) - spin_lock(&sm750_dev->slock); + spin_lock(&sm750_dev->slock); sm750_dev->accel.de_copyarea(&sm750_dev->accel, base, pitch, region->sx, region->sy, base, pitch, Bpp, region->dx, region->dy, region->width, region->height, HW_ROP2_COPY); - if (sm750_dev->fb_count > 1) - spin_unlock(&sm750_dev->slock); + spin_unlock(&sm750_dev->slock); } static void lynxfb_ops_imageblit(struct fb_info *info, @@ -268,9 +268,10 @@ static void lynxfb_ops_imageblit(struct fb_info *info, /* * If not use spin_lock, system will die if user load driver * and immediately unload driver frequently (dual) + * since they fb_count could change during the lifetime of + * this lock, we are holding it for all cases. */ - if (sm750_dev->fb_count > 1) - spin_lock(&sm750_dev->slock); + spin_lock(&sm750_dev->slock); sm750_dev->accel.de_imageblit(&sm750_dev->accel, image->data, image->width >> 3, 0, @@ -278,8 +279,7 @@ static void lynxfb_ops_imageblit(struct fb_info *info, image->dx, image->dy, image->width, image->height, fgcol, bgcol, HW_ROP2_COPY); - if (sm750_dev->fb_count > 1) - spin_unlock(&sm750_dev->slock); + spin_unlock(&sm750_dev->slock); } static int lynxfb_ops_pan_display(struct fb_var_screeninfo *var, -- 2.13.2