* "ls > /dev/fb0" generates weird ioctls if panning is set
@ 2011-12-16 21:49 Timur Tabi
2011-12-16 22:31 ` Timur Tabi
2011-12-16 23:03 ` Anatolij Gustschin
0 siblings, 2 replies; 3+ messages in thread
From: Timur Tabi @ 2011-12-16 21:49 UTC (permalink / raw)
To: linux-fbdev
If I do this:
echo "0,100" > /sys/devices/soc.0/fffe10000.display/graphics/fb0/pan
then whenever I do this:
ls > /dev/fb0
my driver receives the following three ioctls:
graphics fb0: unknown ioctl command (0x402C7413)
graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
graphics fb0: unknown ioctl command (0x40087468)
graphics fb0: dir=2 type='t' (74) nr\x104 size=8
graphics fb0: unknown ioctl command (0x402C7413)
graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
This is on PowerPC, where dir=2 means read.
The "echo" and "cat" commands don't generate these ioctls, so there's something special about the "ls" command. Does anyone know what's going on? ioctl-number.txt lists these ioctls for type 't':
't' 00-7F linux/if_ppp.h
't' 80-8F linux/isdn_ppp.h
't' 90 linux/toshiba.h
--
Timur Tabi
Linux kernel developer at Freescale
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: "ls > /dev/fb0" generates weird ioctls if panning is set
2011-12-16 21:49 "ls > /dev/fb0" generates weird ioctls if panning is set Timur Tabi
@ 2011-12-16 22:31 ` Timur Tabi
2011-12-16 23:03 ` Anatolij Gustschin
1 sibling, 0 replies; 3+ messages in thread
From: Timur Tabi @ 2011-12-16 22:31 UTC (permalink / raw)
To: linux-fbdev
Timur Tabi wrote:
> graphics fb0: unknown ioctl command (0x402C7413)
> graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
> graphics fb0: unknown ioctl command (0x40087468)
> graphics fb0: dir=2 type='t' (74) nr\x104 size=8
> graphics fb0: unknown ioctl command (0x402C7413)
> graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
I figured it out. These ioctls are:
#define TCGETS _IOR('t', 19, struct termios)
#define TIOCGWINSZ _IOR('t', 104, struct winsize)
I'm guessing that since I redirect stdout to /dev/fb0, Linux is treating /dev/fb0 as a terminal, and therefore it's receiving terminal ioctls.
Is this something that fbdev should be supporting, or am I wrong to use /dev/fb0 as a terminal?
--
Timur Tabi
Linux kernel developer at Freescale
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: "ls > /dev/fb0" generates weird ioctls if panning is set
2011-12-16 21:49 "ls > /dev/fb0" generates weird ioctls if panning is set Timur Tabi
2011-12-16 22:31 ` Timur Tabi
@ 2011-12-16 23:03 ` Anatolij Gustschin
1 sibling, 0 replies; 3+ messages in thread
From: Anatolij Gustschin @ 2011-12-16 23:03 UTC (permalink / raw)
To: linux-fbdev
On Fri, 16 Dec 2011 16:31:22 -0600
Timur Tabi <timur@freescale.com> wrote:
> Timur Tabi wrote:
>
> > graphics fb0: unknown ioctl command (0x402C7413)
> > graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
> > graphics fb0: unknown ioctl command (0x40087468)
> > graphics fb0: dir=2 type='t' (74) nr\x104 size=8
> > graphics fb0: unknown ioctl command (0x402C7413)
> > graphics fb0: dir=2 type='t' (74) nr\x19 sizeD
>
> I figured it out. These ioctls are:
>
> #define TCGETS _IOR('t', 19, struct termios)
> #define TIOCGWINSZ _IOR('t', 104, struct winsize)
>
> I'm guessing that since I redirect stdout to /dev/fb0, Linux is
> treating /dev/fb0 as a terminal, and therefore it's receiving
> terminal ioctls.
>
> Is this something that fbdev should be supporting, or am I wrong
> to use /dev/fb0 as a terminal?
No. Do not redirect to /dev/fb0, use /dev/tty1 instead.
Anatolij
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-12-16 21:49 "ls > /dev/fb0" generates weird ioctls if panning is set Timur Tabi
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2011-12-16 23:03 ` Anatolij Gustschin
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