Re: Initialisation bug in IDE patch

[Andre Hedrick <andre@linux-ide.org>]

Please check the function in the top of ide.c

linux-2.4.19-p7 ide.c

static void init_hwif_data (unsigned int index)
{
        unsigned int unit;
        hw_regs_t hw;
        ide_hwif_t *hwif = &ide_hwifs[index];

        /* bulk initialize hwif & drive info with zeros */
        memset(hwif, 0, sizeof(ide_hwif_t));
        memset(&hw, 0, sizeof(hw_regs_t));

        /* fill in any non-zero initial values */
        hwif->index     = index;
        ide_init_hwif_ports(&hw, ide_default_io_base(index), 0, &hwif->irq);
        memcpy(&hwif->hw, &hw, sizeof(hw));
        memcpy(hwif->io_ports, hw.io_ports, sizeof(hw.io_ports));
        hwif->noprobe   = !hwif->io_ports[IDE_DATA_OFFSET];

Obviously you are calling things outside of the normal usage of the
driver.  

2.2.19 ide.c

/*
 * Do not even *think* about calling this!
 */
static void init_hwif_data (unsigned int index)
{
        unsigned int unit;
        hw_regs_t hw;
        ide_hwif_t *hwif = &ide_hwifs[index];

        /* bulk initialize hwif & drive info with zeros */
        memset(hwif, 0, sizeof(ide_hwif_t));
        memset(&hw, 0, sizeof(hw_regs_t));

        /* fill in any non-zero initial values */
        hwif->index     = index;
        ide_init_hwif_ports(&hw, ide_default_io_base(index), 0, &hwif->irq);
        memcpy(&hwif->hw, &hw, sizeof(hw));
        memcpy(hwif->io_ports, hw.io_ports, sizeof(hw.io_ports));
        hwif->noprobe   = !hwif->io_ports[IDE_DATA_OFFSET];
#ifdef CONFIG_BLK_DEV_HD
        if (hwif->io_ports[IDE_DATA_OFFSET] == HD_DATA)

If you are attempting to introduce a hw.chipset which is unknown to the
driver please submit a patch to register it or the enum index will barf.

Cheers,

On Wed, 22 May 2002, Andrew Pam wrote:

> On Wed, May 22, 2002 at 03:15:10PM +1000, Andrew Pam wrote:
> > In the latest available kernel 2.2 IDE patch "ide-2.2.20.01102002.patch"
> > there is a bug that prevents ide_setup in drivers/block/ide.c
> > from accepting kernel parameters selecting special IDE hardware.
> > 
> > The ide_init_default_hwifs() function in include/asm-*/ide.h fails to
> > initialise the "hw_regs_t hw" variable, thus leaving uninitialised data
> > in some fields.  Specifically, the "chipset" field is uninitialised which
> > causes the "if (hwif->chipset != ide_unknown)" test in drivers/block/ide.c
> > to always fail with the error message " -- BAD OPTION".
> 
> This bug also appears to be present in the mainline 2.4 kernel IDE code.
> I haven't checked the 2.5 code yet.
> 
> Regards,
> 	Andrew Pam
> -- 
> mailto:xanni@xanadu.net                         Andrew Pam
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Andre Hedrick
LAD Storage Consulting Group