Re: no-op delay loops

From: Ralf Baechle
Date: Mon Nov 30 2015 - 20:26:05 EST


On Mon, Nov 30, 2015 at 10:29:26PM +0100, Rasmus Villemoes wrote:

> OK, thanks. That's a very very long time ago.
>
> FWIW, the remaining instances that my trivial coccinelle script found
> are

After your initial report I also wrote a coccinelle which is looking
also for delay loops implemented in while loops. It found the following
two:

diff -u -p ./drivers/video/uvesafb.c /tmp/nothing/drivers/video/uvesafb.c
--- ./drivers/video/uvesafb.c
+++ /tmp/nothing/drivers/video/uvesafb.c
@@ -1142,7 +1142,6 @@ static int uvesafb_blank(int blank, stru
vga_wseq(NULL, 0x00, seq);

crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
- while (loop--);
vga_wcrt(NULL, 0x17, crtc17);
vga_wseq(NULL, 0x00, 0x03);
} else
diff -u -p ./arch/mips/pmc-sierra/yosemite/atmel_read_eeprom.c /tmp/nothing/arch/mips/pmc-sierra/yosemite/atmel_read_eeprom.c
--- ./arch/mips/pmc-sierra/yosemite/atmel_read_eeprom.c
+++ /tmp/nothing/arch/mips/pmc-sierra/yosemite/atmel_read_eeprom.c
@@ -37,7 +37,6 @@

static void delay(int delay)
{
- while (delay--);
}

static void send_bit(unsigned char bit)

The 2nd file falls into my domain so I'm going to fix it. Not sure
how the uvesafb one should be treated.

Ralf
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