From mboxrd@z Thu Jan 1 00:00:00 1970 From: AbdAllah-MEZITI Date: Mon, 26 Jun 2017 17:26:19 +0000 Subject: [PATCH v2] staging: sm750fb: always take the lock Message-Id: <1498497981-3240-1-git-send-email-abdallah.meziti.pro@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sudipm.mukherjee@gmail.com Cc: AbdAllah MEZITI , Teddy Wang , Greg Kroah-Hartman , linux-fbdev@vger.kernel.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org This patch - Always take the lock: The current code only takes the lock if multiple instances are in use. This is error-prone, and confuses static analyzers. As taking the lock in case of a single instance is harmless and cheap, change the code to always take the lock. - That also fix the sparse warning: drivers/staging/sm750fb/sm750.c:159:13: warning: context imbalance in 'lynxfb_ops_fillrect' - different lock contexts for basic block drivers/staging/sm750fb/sm750.c:231:9: warning: context imbalance in 'lynxfb_ops_copyarea' - different lock contexts for basic block drivers/staging/sm750fb/sm750.c:235:13: warning: context imbalance in 'lynxfb_ops_imageblit' - different lock contexts for basic block Signed-off-by: AbdAllah MEZITI v2: - add and fix the changelog text. --- drivers/staging/sm750fb/sm750.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index 386d4ad..4a22190 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -186,16 +186,14 @@ static void lynxfb_ops_fillrect(struct fb_info *info, * If not use spin_lock,system will die if user load driver * and immediately unload driver frequently (dual) */ - 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, @@ -220,16 +218,14 @@ 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) */ - 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, @@ -269,8 +265,7 @@ 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) */ - 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 +273,7 @@ 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, -- 2.7.4