Re: kern/52440: nouveau blank screen w/some cards after MSI change in 7.99.64

["John D. Baker" <jdbaker%consolidated.net@localhost>]

The following reply was made to PR kern/52440; it has been noted by GNATS.

From: "John D. Baker" <jdbaker%consolidated.net@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/52440: nouveau blank screen w/some cards after MSI change
 in 7.99.64
Date: Thu, 20 Jun 2019 14:45:08 -0500 (CDT)

 I'm not sure what kind of feedback I can give right now.  The only machine
 to which I've had access is one that is not and was never affected by the
 issue reported in this PR.
 
 In the past, I could test MSI/MSIX operation using a kernel built with
 the following local patch:
 
 +Index: sys/external/bsd/drm2/linux/linux_pci.c
 +===================================================================
 +RCS file: /cvsroot/src/sys/external/bsd/drm2/linux/linux_pci.c,v
 +retrieving revision 1.6
 +diff -u -p -r1.6 linux_pci.c
 +--- sys/external/bsd/drm2/linux/linux_pci.c	28 Aug 2018 03:41:39 -0000	1.6
 ++++ sys/external/bsd/drm2/linux/linux_pci.c	28 Aug 2018 20:07:42 -0000
 +@@ -257,7 +257,6 @@ pci_bus_write_config_byte(struct pci_bus
 + int
 + pci_enable_msi(struct pci_dev *pdev)
 + {
 +-#ifdef notyet
 + 	const struct pci_attach_args *const pa = &pdev->pd_pa;
 + 
 + 	if (pci_msi_alloc_exact(pa, &pdev->pd_intr_handles, 1))
 +@@ -265,9 +264,6 @@ pci_enable_msi(struct pci_dev *pdev)
 + 
 + 	pdev->msi_enabled = 1;
 + 	return 0;
 +-#else
 +-	return -ENOSYS;
 +-#endif
 + }
 + 
 + void
 
 
 But as of this commit:
 
   http://mail-index.netbsd.org/source-changes/2018/12/19/msg101560.html
 
 MSI(X) is explicitly disabled for all nouveau.
 
 Unfortunately, a kernel with this file rolled back to the previous
 revision panics on a nouveau-equipped machine.
 
 
 The only other issue is (if I get access to them) whether newer
 nVidia graphics cards are now supported, independent of the MSI(X)/INTx
 issue.
 
 
 I have a build of 8.99.47 underway.  I hope to try that one soon-ish.
 
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