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

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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.
This commit is contained in:
Benjamin Herrenschmidt 2014-10-03 15:18:59 +10:00
parent f144d1496b
commit 91ed6fd2c3
1 changed files with 10 additions and 0 deletions
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10
drivers/gpu/drm/radeon/radeon_irq_kms.c
View File

@ -185,6 +185,16 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
if (rdev->flags & RADEON_IS_AGP)
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 */
if (radeon_msi == 1)
return true;