> -----Original Message----- > From: H. Peter Anvin [mailto:h...@zytor.com] > Sent: Friday, April 11, 2014 4:59 PM > To: KY Srinivasan; x...@kernel.org; gre...@linuxfoundation.org; linux- > ker...@vger.kernel.org; de...@linuxdriverproject.org; o...@aepfle.de; > a...@canonical.com; jasow...@redhat.com; t...@linutronix.de; > jbeul...@suse.com > Subject: Re: [PATCH V1 1/1] X86: Probe for PIC and set legacy_pic > appropriately > > On 04/11/2014 05:50 PM, K. Y. Srinivasan wrote: > > > > + /* > > + * Check to see if we have a PIC. > > + * Mask all except the cascade and read > > + * back the value we just wrote. If we don't > > + * have a PIC, we will read 0xff as opposed to the > > + * value we wrote. > > + */ > > + outb(probe_val, PIC_MASTER_IMR); > > + probe_val = inb(PIC_MASTER_IMR); > > + if (probe_val == 0xff) { > > + printk(KERN_INFO "Using NULL legacy PIC\n"); > > + legacy_pic = &null_legacy_pic; > > + raw_spin_unlock_irqrestore(&i8259A_lock, flags); > > + return; > > + } > > + > > outb(0xff, PIC_MASTER_IMR); /* mask all of 8259A-1 */ > > outb(0xff, PIC_SLAVE_IMR); /* mask all of 8259A-2 */ > > > > Again, I would do at least the slave masking above the probe. > > Also, I would compare to make sure we get the probe_val back and compare > with != instead of comparing with ==.
Will do. Thanks, K. Y _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
