Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no memory I/O resources detected

From	Sreekanth Reddy <sreekanth.reddy@avagotech.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no memory I/O resources detected
Date	2015-07-15 08:40 +0200
Message-ID	<pMowj-7Sm-45@gated-at.bofh.it> (permalink)
References	<pMmXx-5z0-5@gated-at.bofh.it> <pMnAd-6xs-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Tue, Jul 14, 2015 at 10:36:58PM -0700, Yinghai Lu wrote:
> On Tue, Jul 14, 2015 at 9:49 PM, Sreekanth Reddy
> <sreekanth.reddy@avagotech.com> wrote:
> > Driver crashes if the BIOS do not set up at least one
> > memory I/O resource. This failure can happen if the device is too
> > slow to respond during POST and is missed by the BIOS, but Linux
> > then detects the device later in the boot process.
> 
> But pci subsystem should assign resources to those unassigned BAR.
> 
> Do you mean even kernel can not assign resource to them? or it takes so long for
> mpt FW to get ready?

This is not an issue from mpt FW.

I have just kept the same description provide by Timothy in his
initial patch.

But I observe that their may be chance of getting "unable to handle
kernel NULL pointer dereference" kernel panic if no Memory Resource
available in the PCI subsystem. So agreed to the Timothy proposal of
aborting the driver initialization if it doesn't detect any Memory
resource instead of whole system get into panic state.

> 
> Thanks
> 
> Yinghai
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no  memory I/O resources detected Yinghai Lu <yinghai@kernel.org> - 2015-07-15 07:40 +0200
  Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no  memory I/O resources detected Sreekanth Reddy <sreekanth.reddy@avagotech.com> - 2015-07-15 08:40 +0200
    Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no  memory I/O resources detected Timothy Pearson <tpearson@raptorengineeringinc.com> - 2015-07-15 16:10 +0200
      Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no  memory I/O resources detected Bjorn Helgaas <bhelgaas@google.com> - 2015-07-15 17:00 +0200

csiph-web