cyber2000fb: fix machine hang on module load
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From: Jeff Garzik on 31 Jul 2010 17:30 On 07/31/2010 04:55 PM, Ondrej Zary wrote: > I was testing two CyberPro 2000 based PCI cards on x86 and the machine always > hanged completely when the cyber2000fb module was loaded. It seems that the > card hangs when some registers are accessed too quickly after writing RAMDAC > control register. With this patch, both card work. > > Add delay after RAMDAC control register write to prevent hangs on module load. > > Signed-off-by: Ondrej Zary<linux(a)rainbow-software.org> > > --- linux-2.6.35-rc2-orig/drivers/video/cyber2000fb.c 2010-06-06 05:43:24.000000000 +0200 > +++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c 2010-07-27 23:12:37.000000000 +0200 > @@ -436,6 +436,8 @@ static void cyber2000fb_write_ramdac_ctr > cyber2000fb_writeb(i | 4, 0x3cf, cfb); > cyber2000fb_writeb(val, 0x3c6, cfb); > cyber2000fb_writeb(i, 0x3cf, cfb); > + /* prevent card lock-up observed on x86 with CyberPro 2000 */ > + cyber2000fb_readb(0x3cf, cfb); > } IIRC, cyber2000 is basically an S3 graphics chip. When working on s3fb, over a decade ago, ISTR needing a lot of MMIO register flushes -- dummy register reads -- to flush out just-written register writes. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Russell King - ARM Linux on 31 Jul 2010 17:30 On Sat, Jul 31, 2010 at 05:21:33PM -0400, Jeff Garzik wrote: > On 07/31/2010 04:55 PM, Ondrej Zary wrote: >> I was testing two CyberPro 2000 based PCI cards on x86 and the machine always >> hanged completely when the cyber2000fb module was loaded. It seems that the >> card hangs when some registers are accessed too quickly after writing RAMDAC >> control register. With this patch, both card work. >> >> Add delay after RAMDAC control register write to prevent hangs on module load. >> >> Signed-off-by: Ondrej Zary<linux(a)rainbow-software.org> >> >> --- linux-2.6.35-rc2-orig/drivers/video/cyber2000fb.c 2010-06-06 05:43:24.000000000 +0200 >> +++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c 2010-07-27 23:12:37.000000000 +0200 >> @@ -436,6 +436,8 @@ static void cyber2000fb_write_ramdac_ctr >> cyber2000fb_writeb(i | 4, 0x3cf, cfb); >> cyber2000fb_writeb(val, 0x3c6, cfb); >> cyber2000fb_writeb(i, 0x3cf, cfb); >> + /* prevent card lock-up observed on x86 with CyberPro 2000 */ >> + cyber2000fb_readb(0x3cf, cfb); >> } > > IIRC, cyber2000 is basically an S3 graphics chip. No such luck. It's a proprietary Integraphics chip, mainly used in ARM Netwinders some 10 years ago. It's completely different from the S3 chips such as Trio64. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Jeff Garzik on 31 Jul 2010 18:40 On 07/31/2010 05:25 PM, Russell King - ARM Linux wrote: > On Sat, Jul 31, 2010 at 05:21:33PM -0400, Jeff Garzik wrote: >> On 07/31/2010 04:55 PM, Ondrej Zary wrote: >>> I was testing two CyberPro 2000 based PCI cards on x86 and the machine always >>> hanged completely when the cyber2000fb module was loaded. It seems that the >>> card hangs when some registers are accessed too quickly after writing RAMDAC >>> control register. With this patch, both card work. >>> >>> Add delay after RAMDAC control register write to prevent hangs on module load. >>> >>> Signed-off-by: Ondrej Zary<linux(a)rainbow-software.org> >>> >>> --- linux-2.6.35-rc2-orig/drivers/video/cyber2000fb.c 2010-06-06 05:43:24.000000000 +0200 >>> +++ linux-2.6.35-rc3/drivers/video/cyber2000fb.c 2010-07-27 23:12:37.000000000 +0200 >>> @@ -436,6 +436,8 @@ static void cyber2000fb_write_ramdac_ctr >>> cyber2000fb_writeb(i | 4, 0x3cf, cfb); >>> cyber2000fb_writeb(val, 0x3c6, cfb); >>> cyber2000fb_writeb(i, 0x3cf, cfb); >>> + /* prevent card lock-up observed on x86 with CyberPro 2000 */ >>> + cyber2000fb_readb(0x3cf, cfb); >>> } >> >> IIRC, cyber2000 is basically an S3 graphics chip. > > No such luck. It's a proprietary Integraphics chip, mainly used in > ARM Netwinders some 10 years ago. It's completely different from the > S3 chips such as Trio64. Ah, I stand corrected. Maybe that was cyberfb I was remembering... Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Russell King - ARM Linux on 31 Jul 2010 19:00
On Sat, Jul 31, 2010 at 06:37:27PM -0400, Jeff Garzik wrote: > On 07/31/2010 05:25 PM, Russell King - ARM Linux wrote: >> No such luck. It's a proprietary Integraphics chip, mainly used in >> ARM Netwinders some 10 years ago. It's completely different from the >> S3 chips such as Trio64. > > Ah, I stand corrected. Maybe that was cyberfb I was remembering... I think so - the old cyberfb.h contained this: -/* s3 commands */ -#define S3_BITBLT 0xc011 -#define S3_TWOPOINTLINE 0x2811 -#define S3_FILLEDRECT 0x40b1 so yes, it was similar to the S3 driver. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |