From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Briskin Date: Sun, 23 Oct 2016 12:37:57 +0000 Subject: [PATCH] staging: sm750fb: Fix lock context error Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org Sparse error fix - different lock contexts for basic block. Acquirement and release of spin lock was dependent on two separate unprotected variable evaluations. Instead the condition evaluation result is stored in a local boolean variable to make sure that the same context that called the spin_lock will evoke spin_unlock. Signed-off-by: Alex Briskin --- drivers/staging/sm750fb/sm750.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index 0663ec0..4f0f98e 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -164,6 +164,7 @@ static void lynxfb_ops_fillrect(struct fb_info *info, struct sm750_dev *sm750_dev; unsigned int base, pitch, Bpp, rop; u32 color; + bool lock_in_this_context = false; if (info->state != FBINFO_STATE_RUNNING) return; @@ -187,7 +188,8 @@ 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) + lock_in_this_context = sm750_dev->fb_count > 1; + if (lock_in_this_context) spin_lock(&sm750_dev->slock); sm750_dev->accel.de_fillrect(&sm750_dev->accel, @@ -195,7 +197,7 @@ static void lynxfb_ops_fillrect(struct fb_info *info, region->dx, region->dy, region->width, region->height, color, rop); - if (sm750_dev->fb_count > 1) + if (lock_in_this_context) spin_unlock(&sm750_dev->slock); } @@ -205,6 +207,7 @@ static void lynxfb_ops_copyarea(struct fb_info *info, struct lynxfb_par *par; struct sm750_dev *sm750_dev; unsigned int base, pitch, Bpp; + bool lock_in_this_context = false; par = info->par; sm750_dev = par->dev; @@ -221,7 +224,8 @@ 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) + lock_in_this_context = sm750_dev->fb_count > 1; + if (lock_in_this_context) spin_lock(&sm750_dev->slock); sm750_dev->accel.de_copyarea(&sm750_dev->accel, @@ -229,7 +233,7 @@ static void lynxfb_ops_copyarea(struct fb_info *info, base, pitch, Bpp, region->dx, region->dy, region->width, region->height, HW_ROP2_COPY); - if (sm750_dev->fb_count > 1) + if (lock_in_this_context) spin_unlock(&sm750_dev->slock); } -- 2.7.4