Re: sisusb: Use static const, fix typo

From: Joe Perches
Date: Mon Feb 24 2014 - 13:01:26 EST


On Mon, 2014-02-24 at 10:26 +0000, David Laight wrote:
> From: Joe Perches
> > Reduce text a bit by using static const.
>
> If you want to save a few bytes remove the pointers.
> (and the fixed RAM text to get below 7 chars).

Hi David.

> eg:
>
> > - const char *ramtypetext2[] = { "SDR SDRAM", "SDR SGRAM",
> > - "DDR SDRAM", "DDR SGRAM" };

The idea was use static to avoid the array reload
on each function entry.

> static const char ramtypetext2[8][] = {
> "SDR SD", "SDR SG", "DDR SD", "DDR SG"

8 is an odd number here.

That could be done with char like:

static const char ram_datarate[4] = {'S', 'S', 'D', 'D'};
static const char ram_dynamictype[4] = {'D', 'G', 'D', 'G'};
> ...
> > - dev_info(&sisusb->sisusb_dev->dev, "%dMB %s %s, bus width %d\n", (sisusb->vramsize >> 20),
> > ramtypetext1,
> > - ramtypetext2[ramtype], bw);
>
> dev_info(&sisusb->sisusb_dev->dev, "%dMB %s %sRAM, bus width %d\n",
> sisusb->vramsize >> 20, ramtypetext1, ramtypetext2[ramtype],
> bw);

dev_info(&sisusb->sisusb_dev->dev, "%dMB %s %c%cRAM, bus width %d\n",
sisusb->vramsize >> 20, ramtypetext1,
ram_datarate[ramtype], ram_dynamictype[ramtype], bw);

So something like:

Convert 1 char * array to 2 char arrays to reduce size.
Use static const to avoid array reloads on function entry.
Fix asymmetric typo.

$ size drivers/usb/misc/sisusbvga/sisusb.o*
text data bss dec hex filename
29971 4841 9180 43992 abd8 drivers/usb/misc/sisusbvga/sisusb.o.new
30083 4841 9180 44104 ac48 drivers/usb/misc/sisusbvga/sisusb.o.old

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
drivers/usb/misc/sisusbvga/sisusb.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/misc/sisusbvga/sisusb.c b/drivers/usb/misc/sisusbvga/sisusb.c
index de98906..06b5d77 100644
--- a/drivers/usb/misc/sisusbvga/sisusb.c
+++ b/drivers/usb/misc/sisusbvga/sisusb.c
@@ -2123,8 +2123,8 @@ sisusb_get_ramconfig(struct sisusb_usb_data *sisusb)
u8 tmp8, tmp82, ramtype;
int bw = 0;
char *ramtypetext1 = NULL;
- const char *ramtypetext2[] = { "SDR SDRAM", "SDR SGRAM",
- "DDR SDRAM", "DDR SGRAM" };
+ static const char ram_datarate[4] = {'S', 'S', 'D', 'D'};
+ static const char ram_dynamictype[4] = {'D', 'G', 'D', 'G'};
static const int busSDR[4] = {64, 64, 128, 128};
static const int busDDR[4] = {32, 32, 64, 64};
static const int busDDRA[4] = {64+32, 64+32 , (64+32)*2, (64+32)*2};
@@ -2156,8 +2156,10 @@ sisusb_get_ramconfig(struct sisusb_usb_data *sisusb)
break;
}

- dev_info(&sisusb->sisusb_dev->dev, "%dMB %s %s, bus width %d\n", (sisusb->vramsize >> 20), ramtypetext1,
- ramtypetext2[ramtype], bw);
+
+ dev_info(&sisusb->sisusb_dev->dev, "%dMB %s %cDR S%cRAM, bus width %d\n",
+ sisusb->vramsize >> 20, ramtypetext1,
+ ram_datarate[ramtype], ram_dynamictype[ramtype], bw);
}

static int


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