[PATCH] drivers: usb-misc: sisusbvga: remove dead code

[PATCH] drivers: usb-misc: sisusbvga: remove dead code

[Gustavo A. R. Silva]

The condition modex % 16 cannot be true when modex value is equal to 640
The condition du & 0xff cannot be true when du value is equal to 0x1400

Addresses-Coverity-Id: 101163
Addresses-Coverity-Id: 744373
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/usb/misc/sisusbvga/sisusb.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/usb/misc/sisusbvga/sisusb.c b/drivers/usb/misc/sisusbvga/sisusb.c
index 05bd39d..440d7fe 100644
--- a/drivers/usb/misc/sisusbvga/sisusb.c
+++ b/drivers/usb/misc/sisusbvga/sisusb.c
@@ -1831,16 +1831,10 @@ static int sisusb_set_default_mode(struct sisusb_usb_data *sisusb,
 	SETIREGANDOR(SISCR, 0x09, 0x5f, ((crtcdata[16] & 0x01) << 5));
 	SETIREG(SISCR, 0x14, 0x4f);
 	du = (modex / 16) * (bpp * 2);	/* offset/pitch */
-	if (modex % 16)
-		du += bpp;
-
 	SETIREGANDOR(SISSR, 0x0e, 0xf0, ((du >> 8) & 0x0f));
 	SETIREG(SISCR, 0x13, (du & 0xff));
 	du <<= 5;
 	tmp8 = du >> 8;
-	if (du & 0xff)
-		tmp8++;
-
 	SETIREG(SISSR, 0x10, tmp8);
 	SETIREG(SISSR, 0x31, 0x00);	/* VCLK */
 	SETIREG(SISSR, 0x2b, 0x1b);
-- 
2.5.0

Re: [PATCH] drivers: usb-misc: sisusbvga: remove dead code

[Oliver Neukum]

Am Dienstag, den 07.02.2017, 22:01 -0600 schrieb Gustavo A. R. Silva:
> The condition modex % 16 cannot be true when modex value is equal to
> 640
> The condition du & 0xff cannot be true when du value is equal to
> 0x1400
> 

Sorry for speaking up so late, but this is not a good idea.
We lose the knowledge how to do this correctly, if we want
to change the resolution.

	Regards
		Oliver

Re: [PATCH] drivers: usb-misc: sisusbvga: remove dead code

[Greg KH]

On Thu, Feb 16, 2017 at 11:28:49AM +0100, Oliver Neukum wrote:
> Am Dienstag, den 07.02.2017, 22:01 -0600 schrieb Gustavo A. R. Silva:
> > The condition modex % 16 cannot be true when modex value is equal to
> > 640
> > The condition du & 0xff cannot be true when du value is equal to
> > 0x1400
> > 
> 
> Sorry for speaking up so late, but this is not a good idea.
> We lose the knowledge how to do this correctly, if we want
> to change the resolution.

Given the age of this driver, I doubt that will ever happen :)

thanks,

greg k-h

Re: [PATCH] drivers: usb-misc: sisusbvga: remove dead code

[Felipe Balbi]

Hi,

Greg KH <gregkh@linuxfoundation.org> writes:
> On Thu, Feb 16, 2017 at 11:28:49AM +0100, Oliver Neukum wrote:
>> Am Dienstag, den 07.02.2017, 22:01 -0600 schrieb Gustavo A. R. Silva:
>> > The condition modex % 16 cannot be true when modex value is equal to
>> > 640
>> > The condition du & 0xff cannot be true when du value is equal to
>> > 0x1400
>> > 
>> 
>> Sorry for speaking up so late, but this is not a good idea.
>> We lose the knowledge how to do this correctly, if we want
>> to change the resolution.
>
> Given the age of this driver, I doubt that will ever happen :)

besides, the "knowledge" will always be in git history.

-- 
balbi