[PATCH] staging: sm750fb: Fix lock context error
STALE3633d
From: Alex Briskin <hidden>
Date: 2016-10-23 12:37:57
Subsystem:
staging - silicon motion sm750 frame buffer driver, staging subsystem, the rest · Maintainers:
Sudip Mukherjee, Teddy Wang, Sudip Mukherjee, Greg Kroah-Hartman, Linus Torvalds
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 <redacted> --- 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