Re: [ PATCH 2/4 ] mpt fusion disable hard resets for 53C1030 based devices

[Bernd Schubert <bs@q-leap.de>]

This is patch 2/4 ...

On Tuesday 23 September 2008 15:26:30 Bernd Schubert wrote:
> For 53C1030 based dual port HBAs the hard reset handler will cause
> trouble on the second channel with innocent devices. It is then better
> to fail the device which activated the error handler than to fail
> cause errors on unrelated devices. Of course, the real solutions
> would be to figure out why the hard reset handler cause trouble on the
> second channel. Probably only LSI can do, though.
>
> Signed-off-by: Bernd Schubert <bs@q-leap.de>
>
>  drivers/message/fusion/mptbase.c |   42 ++++++++++++++++++++++++++++-
>  drivers/message/fusion/mptspi.c  |   31 +++++++++++++++++++++
>  2 files changed, 72 insertions(+), 1 deletion(-)
>
> Index: linux-2.6.26/drivers/message/fusion/mptbase.c
> ===================================================================
> --- linux-2.6.26.orig/drivers/message/fusion/mptbase.c
> +++ linux-2.6.26/drivers/message/fusion/mptbase.c
> @@ -59,6 +59,7 @@
>  #include <linux/interrupt.h>		/* needed for in_interrupt() proto */
>  #include <linux/dma-mapping.h>
>  #include <asm/io.h>
> +#include <scsi/scsi_device.h>
>  #ifdef CONFIG_MTRR
>  #include <asm/mtrr.h>
>  #endif
> @@ -6452,6 +6453,33 @@ mpt_HardResetHandler(MPT_ADAPTER *ioc, i
>  }
>
>  /**
> +  * Check if there are devices connected to the second (alt) ioc.
> +  * Return 1 if there is at least on device and 0 if there are
> +  * none or no alt_ioc.
> +  */
> +static int
> +alt_ioc_with_dev(MPT_ADAPTER *ioc)
> +{
> +	struct Scsi_Host	*shost;
> +	struct scsi_device	*sdev;
> +	int 			have_devices = 0;
> +
> +	if (!ioc->alt_ioc)
> +		return 0;
> +
> +	shost = ioc->alt_ioc->sh;
> +
> +	shost_for_each_device(sdev, shost) {
> +		/* when we are here, we know there is is a device
> +		 * attached to this host, which is all we need to know */
> +		have_devices = 1;
> +		break;
> +	}
> +
> +	return have_devices;
> +}
> +
> +/**
>   *	mpt_SoftHardResetHandler - Generic reset handler
>   *	@ioc: Pointer to MPT_ADAPTER structure
>   *	@sleepFlag: Indicates if sleep or schedule must be called.
> @@ -6466,7 +6494,19 @@ mpt_SoftHardResetHandler(MPT_ADAPTER *io
>
>  	rc = mpt_SoftResetHandler(ioc, sleepFlag);
>  	if (rc) {
> -		rc = mpt_HardResetHandler(ioc, sleepFlag);
> +		if (ioc->no_hard_reset && alt_ioc_with_dev(ioc)) {
> +			/* On dual port HBAs based on the 53C1030 chip the
> +			* hard reset handler will cause DID_SOFT_ERROR on
> +			* the second (in principle independent) port.
> +			* Almost always this error cannot be recovered
> +			* causing entire device failures. So it better not
> +			* to call the hard reset handler at all in order to
> +			* prevent failures of independent devices */
> +			printk(MYIOC_s_INFO_FMT "Skipping hard reset in "
> +				"order to prevent failures on %s.\n",
> +				ioc->name, ioc->alt_ioc->name);
> +		} else
> +			rc = mpt_HardResetHandler(ioc, sleepFlag);
>  	}
>
>  	return rc;
> Index: linux-2.6.26/drivers/message/fusion/mptspi.c
> ===================================================================
> --- linux-2.6.26.orig/drivers/message/fusion/mptspi.c
> +++ linux-2.6.26/drivers/message/fusion/mptspi.c
> @@ -1301,6 +1301,33 @@ mptspi_resume(struct pci_dev *pdev)
>  #endif
>
> 
> /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>-=*/ +/**
> +  * avoid_hard_reset - check if hard resets should be avoided
> +  * @pdev: Pointer to pci_dev structure
> +  *
> +  * Hard resets will cause trouble on the the secondary IOC of
> +  * 53C1030 based devices.
> +  *
> +  * Returns 1 if affected chip is found and 1 for unaffected chips
> +  */
> +static int
> +avoid_hard_reset(struct pci_dev *pdev)
> +{
> +	int avoid;
> +
> +	switch (pdev->device) {
> +	case MPI_MANUFACTPAGE_DEVID_53C1030:
> +	case MPI_MANUFACTPAGE_DEVID_53C1030ZC:
> +		/* TODO: which chips are affected as well? */
> +		avoid = 1;
> +		break;
> +	default:
> +		avoid = 0;
> +	}
> +
> +	return avoid;
> +}
> +
> 
> /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>-=*/ /*
>   *	mptspi_probe - Installs scsi devices per bus.
> @@ -1509,6 +1536,10 @@ mptspi_probe(struct pci_dev *pdev, const
>  		goto out_mptspi_probe;
>  	}
>
> +	/* hard resets on 53C1030 HBAs will cause trouble on secondaray (alt)
> +	 * IOCs, so better no hard reset on these */
> +	ioc->no_hard_reset = avoid_hard_reset(pdev);
> +
>  	/*
>  	 * issue internal bus reset
>  	 */
> --
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-- 
Bernd Schubert
Q-Leap Networks GmbH