[PATCH 3/3] Support for PCI Express reset type

Linas Vepstas linasvepstas at gmail.com
Sun Aug 2 08:55:58 EST 2009

2009/7/30 Mike Mason <mmlnx at us.ibm.com>:
> This is the third of three patches that implement a bit field that PCI
> Express device drivers can use to indicate they need a fundamental reset
> during error recovery.
> By default, the EEH framework on powerpc does what's known as a "hot reset"
> during recovery of a PCI Express device.  We've found a case where the
> device needs a "fundamental reset" to recover properly.  The current PCI
> error recovery and EEH frameworks do not support this distinction.
> The attached patch makes changes to EEH to utilize the new bit field.
> These patches supersede the previously submitted patch that implemented a
> fundamental reset bit field.
> Please review and let me know of any concerns.
> Signed-off-by: Mike Mason <mmlnx at us.ibm.com>
> Signed-off-by: Richard Lary <rlary at us.ibm.com>

Signed-off-by: Linas Vepstas <linasvepstas at gmail.com>

> +       /* Determine type of EEH reset required by device,
> +        * default hot reset or fundamental reset
> +        */
> +       if (dev->needs_freset)
> +               rtas_pci_slot_reset(pdn, 3);
> +       else
> +               rtas_pci_slot_reset(pdn, 1);

Gack!  I remember deluges of emails and conference calls
where the hardware guys went on about this; and I admit I didn't
quite get it, which I guess is why this patch is showing up many
years late.

FWIW some of the variants of the IPR chipset almost surely
need the freset  bit set.


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