This is a note to let you know that I've just added the patch titled
gpu/radeon: Set flag to indicate broken 64-bit MSI
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gpu-radeon-set-flag-to-indicate-broken-64-bit-msi.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 91ed6fd2c383bb8f02d66e98b4a4d2f7207249dc Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Date: Fri, 3 Oct 2014 15:18:59 +1000
Subject: gpu/radeon: Set flag to indicate broken 64-bit MSI
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
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 <benh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/radeon/radeon_irq_kms.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- 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_
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;
Patches currently in stable-queue which might be from benh@xxxxxxxxxxxxxxxxxxx are
queue-3.14/of-base-fix-powerpc-address-parsing-hack.patch
queue-3.14/powerpc-pseries-honor-the-generic-no_64bit_msi-flag.patch
queue-3.14/gpu-radeon-set-flag-to-indicate-broken-64-bit-msi.patch
queue-3.14/pci-msi-add-device-flag-indicating-that-64-bit-msis-don-t-work.patch
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