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Groups > linux.kernel > #1184826
| From | Timothy Pearson <tpearson@raptorengineeringinc.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v3] [SCSI] mpt2sas, mpt3sas: Abort initialization if no memory I/O resources detected |
| Date | 2015-07-15 16:10 +0200 |
| Message-ID | <pMvxM-1jg-19@gated-at.bofh.it> (permalink) |
| References | <pMmXx-5z0-5@gated-at.bofh.it> <pMnAd-6xs-1@gated-at.bofh.it> <pMowj-7Sm-45@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 07/15/2015 01:24 AM, Sreekanth Reddy wrote: > 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 On some systems Linux is unable / unwilling to assign a BAR if the BIOS does not assign one at startup. I didn't look into the Linux allocator side of things in much detail, but it is quite possible that Linux is unaware the device only has partial resources assigned. -- Timothy Pearson Raptor Engineering +1 (415) 727-8645 http://www.raptorengineeringinc.com -- 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/
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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
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