# \[PATCH\] staging: sm750fb: fix sparse warning for lock - Subsystems: STAGING - SILICON MOTION SM750 FRAME BUFFER DRIVER, STAGING SUBSYSTEM, THE REST - Maintainers: Sudip Mukherjee, Teddy Wang, Sudip Mukherjee, Greg Kroah-Hartman, Linus Torvalds - List: linux-fbdev - 3 messages, 3 authors - Page: https://ratatoskr.run/linux-fbdev/2015/08/4551362/t ## \[PATCH\] staging: sm750fb: fix sparse warning for lock - From: Peng Fan \ - Date: 2015-08-05 13:26:54 - Message: https://ratatoskr.run/linux-fbdev/2015/08/4551362.md ```text Use __acquire() and __release() in the right place to silence the sparse lock checking warning. drivers/staging/sm750fb/sm750.c:177:13: warning: context imbalance in 'lynxfb_ops_fillrect' - different lock contexts for basic block drivers/staging/sm750fb/sm750.c:243:9: warning: context imbalance in 'lynxfb_ops_copyarea' - different lock contexts for basic block drivers/staging/sm750fb/sm750.c:247:13: warning: context imbalance in 'lynxfb_ops_imageblit' - different lock contexts for basic block Signed-off-by: Peng Fan Cc: Sudip Mukherjee Cc: Teddy Wang Cc: Greg Kroah-Hartman --- drivers/staging/sm750fb/sm750.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index 8e201f1..5ba1c06 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -203,6 +203,8 @@ static void lynxfb_ops_fillrect(struct fb_info *info, */ if (share->dual) spin_lock(&share->slock); + else + __acquire(&share->slock); share->accel.de_fillrect(&share->accel, base, pitch, Bpp, @@ -211,6 +213,8 @@ static void lynxfb_ops_fillrect(struct fb_info *info, color, rop); if (share->dual) spin_unlock(&share->slock); + else + __release(&share->slock); } static void lynxfb_ops_copyarea(struct fb_info *info, @@ -235,6 +239,8 @@ static void lynxfb_ops_copyarea(struct fb_info *info, */ if (share->dual) spin_lock(&share->slock); + else + __acquire(&share->slock); share->accel.de_copyarea(&share->accel, base, pitch, region->sx, region->sy, @@ -242,6 +248,8 @@ static void lynxfb_ops_copyarea(struct fb_info *info, region->width, region->height, HW_ROP2_COPY); if (share->dual) spin_unlock(&share->slock); + else + __release(&share->slock); } static void lynxfb_ops_imageblit(struct fb_info *info, @@ -282,6 +290,8 @@ _do_work: */ if (share->dual) spin_lock(&share->slock); + else + __acquire(&share->slock); share->accel.de_imageblit(&share->accel, image->data, image->width>>3, 0, @@ -291,6 +301,8 @@ _do_work: fgcol, bgcol, HW_ROP2_COPY); if (share->dual) spin_unlock(&share->slock); + else + __release(&share->slock); } static int lynxfb_ops_pan_display(struct fb_var_screeninfo *var, -- 1.8.4 ``` ## Re: \[PATCH\] staging: sm750fb: fix sparse warning for lock - From: Greg KH \ - Date: 2015-08-05 19:01:55 - Message: https://ratatoskr.run/linux-fbdev/2015/08/4551701.md ```text On Wed, Aug 05, 2015 at 09:26:44PM +0800, Peng Fan wrote: > Use __acquire() and __release() in the right place to silence the sparse > lock checking warning. > > drivers/staging/sm750fb/sm750.c:177:13: warning: context imbalance in 'lynxfb_ops_fillrect' - different lock contexts for basic block > drivers/staging/sm750fb/sm750.c:243:9: warning: context imbalance in 'lynxfb_ops_copyarea' - different lock contexts for basic block > drivers/staging/sm750fb/sm750.c:247:13: warning: context imbalance in 'lynxfb_ops_imageblit' - different lock contexts for basic block > > Signed-off-by: Peng Fan > Cc: Sudip Mukherjee > Cc: Teddy Wang > Cc: Greg Kroah-Hartman > --- > drivers/staging/sm750fb/sm750.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c > index 8e201f1..5ba1c06 100644 > --- a/drivers/staging/sm750fb/sm750.c > +++ b/drivers/staging/sm750fb/sm750.c > @@ -203,6 +203,8 @@ static void lynxfb_ops_fillrect(struct fb_info *info, > */ > if (share->dual) > spin_lock(&share->slock); > + else > + __acquire(&share->slock); That's horrid, please don't do stuff like this just to make a static checker "quiet". greg k-h ``` ## Re: \[PATCH\] staging: sm750fb: fix sparse warning for lock - From: Dan Carpenter \ - Date: 2015-08-05 22:35:27 - Message: https://ratatoskr.run/linux-fbdev/2015/08/4551939.md ```text On Wed, Aug 05, 2015 at 09:26:44PM +0800, Peng Fan wrote: > Use __acquire() and __release() in the right place to silence the sparse > lock checking warning. > > drivers/staging/sm750fb/sm750.c:177:13: warning: context imbalance in 'lynxfb_ops_fillrect' - different lock contexts for basic block > drivers/staging/sm750fb/sm750.c:243:9: warning: context imbalance in 'lynxfb_ops_copyarea' - different lock contexts for basic block > drivers/staging/sm750fb/sm750.c:247:13: warning: context imbalance in 'lynxfb_ops_imageblit' - different lock contexts for basic block > Sparse is really bad at locking stuff. Smatch is also really bad for locking and I have been promising to re-write that check for years, but I take comfort always in the fact that at least it's not as bad as Sparse. You should pretty much ignore Sparse locking warnings. regards, dan carpenter ```