Commit 91ed6fd2 authored Oct 03, 2014 by Benjamin Herrenschmidt

gpu/radeon: Set flag to indicate broken 64-bit MSI



Some radeon ASICs don't support all 64 address bits of MSIs despite
advertising support for 64-bit MSIs in their configuration space.

This breaks on systems such as IBM POWER7/8, where 64-bit MSIs can
be assigned with some of the high address bits set.

This makes use of the newly introduced "no_64bit_msi" flag in structure
pci_dev to allow the MSI allocation code to fallback to 32-bit MSIs
on those adapters.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
CC: <stable@vger.kernel.org>
---

Adding Alex's review tag. Patch to the driver is identical to the
reviewed one, I dropped the arch/powerpc hunk rewrote the subject
and cset comment.

parent f144d149

drivers/gpu/drm/radeon/radeon_irq_kms.c

+10 −0

Original line number	Original line	Diff line number	Diff line
	@@ -185,6 +185,16 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
	if (rdev->flags & RADEON_IS_AGP)		if (rdev->flags & RADEON_IS_AGP)
	return false;		return false;

			/*
			* Older chips have a HW limitation, they can only generate 40 bits
			* of address for "64-bit" MSIs which breaks on some platforms, notably
			* IBM POWER servers, so we limit them
			*/
			if (rdev->family < CHIP_BONAIRE) {
			dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n");
			rdev->pdev->no_64bit_msi = 1;
			}

	/* force MSI on */		/* force MSI on */
	if (radeon_msi == 1)		if (radeon_msi == 1)
	return true;		return true;