From: Benjamin Herrenschmidt Date: Fri, 3 Oct 2014 05:18:59 +0000 (+1000) Subject: gpu/radeon: Set flag to indicate broken 64-bit MSI X-Git-Tag: upstream/snapshot3+hdmi~4^2~7 X-Git-Url: http://review.tizen.org/git/?p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git;a=commitdiff_plain;h=a35b403e0ad0a6dfcbc4eb4d307d9d2aaa60d914 gpu/radeon: Set flag to indicate broken 64-bit MSI commit 91ed6fd2c383bb8f02d66e98b4a4d2f7207249dc upstream. 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. 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. Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c index 089c9ff..b3f0293 100644 --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c @@ -202,6 +202,16 @@ 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;