[PATCH] fbdev: savage: remove unused variable

[PATCH] fbdev: savage: remove unused variable

[Sudip Mukherjee]

vga_in8() was storing the return value in tmp, but that return value
was never used again. so it should be safe to remove those variables.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---

just one doubt:
vga_in8() is calling savage_in8() which is a readb().
so in effect we are reading one byte from
(par->mmio.vbase + 0x8000 + 0x3da) and then discarding that value.
so if we are discarding that value then why we are reading it?

 drivers/video/fbdev/savage/savagefb.h | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/video/fbdev/savage/savagefb.h b/drivers/video/fbdev/savage/savagefb.h
index dcaab90..8ff4ab1 100644
--- a/drivers/video/fbdev/savage/savagefb.h
+++ b/drivers/video/fbdev/savage/savagefb.h
@@ -351,32 +351,26 @@ static inline void VGAwSEQ(u8 index, u8 val, struct savagefb_par *par)
 
 static inline void VGAenablePalette(struct savagefb_par *par)
 {
-	u8 tmp;
-
-	tmp = vga_in8(0x3da, par);
+	vga_in8(0x3da, par);
 	vga_out8(0x3c0, 0x00, par);
 	par->paletteEnabled = 1;
 }
 
 static inline void VGAdisablePalette(struct savagefb_par *par)
 {
-	u8 tmp;
-
-	tmp = vga_in8(0x3da, par);
+	vga_in8(0x3da, par);
 	vga_out8(0x3c0, 0x20, par);
 	par->paletteEnabled = 0;
 }
 
 static inline void VGAwATTR(u8 index, u8 value, struct savagefb_par *par)
 {
-	u8 tmp;
-
 	if (par->paletteEnabled)
 		index &= ~0x20;
 	else
 		index |= 0x20;
 
-	tmp = vga_in8(0x3da, par);
+	vga_in8(0x3da, par);
 	vga_out8(0x3c0, index, par);
 	vga_out8 (0x3c0, value, par);
 }
-- 
1.8.1.2

Re: [PATCH] fbdev: savage: remove unused variable

[Tomi Valkeinen]

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On 06/01/15 15:12, Sudip Mukherjee wrote:
> vga_in8() was storing the return value in tmp, but that return value
> was never used again. so it should be safe to remove those variables.
> 
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
> 
> just one doubt:
> vga_in8() is calling savage_in8() which is a readb().
> so in effect we are reading one byte from
> (par->mmio.vbase + 0x8000 + 0x3da) and then discarding that value.
> so if we are discarding that value then why we are reading it?

Sometimes reading a HW register without actually using the returned
value has some effect. I don't know if there's a reason for that in this
case, though, as I'm not familiar with the HW.

In any case, it's safer to keep the read there as you did.

Queued for 3.20.

 Tomi



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