Re: [PATCH] parport_pc.c PnP BIOS sanity check

[Thomas Hood <jdthoodREMOVETHIS@yahoo.co.uk>]

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I'm still wondering why this function in parport_pc.c rejects dma
values of zero.  Is DMA0 not usable by the parallel port for some
reason?  I should think that if the PnP BIOS returns a dma of zero
then it means that the parallel port is using DMA0.  Sorry if I'm
being obtuse.                      // Thomas Hood 

parport_pc.c line 2799:
int init_pnp040x(struct pci_dev *dev)
{       int io,iohi,irq,dma;

        io=dev->resource[0].start;
        iohi=dev->resource[1].start;
        irq=dev->irq_resource[0].start;
        dma=dev->dma_resource[0].start;

        if(dma==0) dma=-1;             <--- Why?

        printk(KERN_INFO "PnPBIOS: Parport found %s %s at io=%04x,%04x irq=%d dma=%d\n",
                dev->name,dev->slot_name,io,iohi,irq,dma);
        if (parport_pc_probe_port(io,iohi,irq,dma,NULL))
                return 1;
        return 0;
}

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--- linux-2.4.7-ac10/drivers/parport/parport_pc.c_ORIG	Fri Aug 10 18:19:07 2001
+++ linux-2.4.7-ac10/drivers/parport/parport_pc.c	Mon Aug 13 17:40:38 2001
@@ -2797,8 +2797,6 @@
 	irq=dev->irq_resource[0].start;
 	dma=dev->dma_resource[0].start;
 
-	if (dma==0) dma=-1;
-
 	printk(KERN_INFO "PnPBIOS: Parport found %s %s at io=%04x,%04x irq=%d dma=%d\n",
 		dev->name,dev->slot_name,io,iohi,irq,dma);
 	if (parport_pc_probe_port(io,iohi,irq,dma,NULL))


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--- linux-2.4.7-ac10/drivers/parport/parport_pc.c_ORIG	Fri Aug 10 18:19:07 2001
+++ linux-2.4.7-ac10/drivers/parport/parport_pc.c	Fri Aug 10 18:19:55 2001
@@ -2797,7 +2797,7 @@
 	irq=dev->irq_resource[0].start;
 	dma=dev->dma_resource[0].start;
 
-	if (dma==0) dma=-1;
+	if (dma==0) dma=PARPORT_DMA_NONE;
 
 	printk(KERN_INFO "PnPBIOS: Parport found %s %s at io=%04x,%04x irq=%d dma=%d\n",
 		dev->name,dev->slot_name,io,iohi,irq,dma);