linux-kernel - Re: [PATCH] fbdev: matrox: make array wtst_xlat static const, makes object smaller

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Date:   Fri, 3 Jan 2020 13:22:47 +0100
From:   Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
To:     Ville Syrjälä <ville.syrjala@...ux.intel.com>,
        Colin King <colin.king@...onical.com>
Cc:     linux-fbdev@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fbdev: matrox: make array wtst_xlat static const, makes
 object smaller

On 9/6/19 8:17 PM, Ville Syrjälä wrote:
> On Fri, Sep 06, 2019 at 07:11:14PM +0100, Colin King wrote:
>> From: Colin Ian King <colin.king@...onical.com>
>>
>> Don't populate the array wtst_xlat on the stack but instead make it
>> static const. Makes the object code smaller by 89 bytes.
>>
>> Before:
>>    text	   data	    bss	    dec	    hex	filename
>>   14347	    840	      0	  15187	   3b53	fbdev/matrox/matroxfb_misc.o
>>
>> After:
>>    text	   data	    bss	    dec	    hex	filename
>>   14162	    936	      0	  15098	   3afa	fbdev/matrox/matroxfb_misc.o
>>
>> (gcc version 9.2.1, amd64)
>>
>> Signed-off-by: Colin Ian King <colin.king@...onical.com>

Thanks, patch queued for v5.6 (also sorry for the delay).

>> ---
>>  drivers/video/fbdev/matrox/matroxfb_misc.c | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/video/fbdev/matrox/matroxfb_misc.c b/drivers/video/fbdev/matrox/matroxfb_misc.c
>> index c7aaca12805e..feb0977c82eb 100644
>> --- a/drivers/video/fbdev/matrox/matroxfb_misc.c
>> +++ b/drivers/video/fbdev/matrox/matroxfb_misc.c
>> @@ -673,7 +673,10 @@ static int parse_pins5(struct matrox_fb_info *minfo,
>>  	if (bd->pins[115] & 4) {
>>  		minfo->values.reg.mctlwtst_core = minfo->values.reg.mctlwtst;
>>  	} else {
>> -		u_int32_t wtst_xlat[] = { 0, 1, 5, 6, 7, 5, 2, 3 };
>> +		static const u_int32_t wtst_xlat[] = {
>> +			0, 1, 5, 6, 7, 5, 2, 3
> 
> All of those would easily fit in u8 as well.

Good idea, I've converted the table to u8 while applying the patch.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

>> +		};
>> +
>>  		minfo->values.reg.mctlwtst_core = (minfo->values.reg.mctlwtst & ~7) |
>>  						  wtst_xlat[minfo->values.reg.mctlwtst & 7];
>>  	}
>> -- 
>> 2.20.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@...ts.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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