linux-kernel - [PATCH] iommu/amd: Fix extended features logging

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Message-Id: <20210410211152.1938-1-amonakov@ispras.ru>
Date:   Sun, 11 Apr 2021 00:11:52 +0300
From:   Alexander Monakov <amonakov@...ras.ru>
To:     linux-kernel@...r.kernel.org
Cc:     Alexander Monakov <amonakov@...ras.ru>,
        Paul Menzel <pmenzel@...gen.mpg.de>,
        Joerg Roedel <jroedel@...e.de>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        iommu@...ts.linux-foundation.org
Subject: [PATCH] iommu/amd: Fix extended features logging

print_iommu_info prints the EFR register and then the decoded list of
features on a separate line:

pci 0000:00:00.2: AMD-Vi: Extended features (0x206d73ef22254ade):
 PPR X2APIC NX GT IA GA PC GA_vAPIC

The second line is emitted via 'pr_cont', which causes it to have a
different ('warn') loglevel compared to the previous line ('info').

Commit 9a295ff0ffc9 attempted to rectify this by removing the newline
from the pci_info format string, but this doesn't work, as pci_info
calls implicitly append a newline anyway.

Restore the newline, and call pr_info with empty format string to set
the loglevel for subsequent pr_cont calls. The same solution is used in
EFI and uvesafb drivers.

Fixes: 9a295ff0ffc9 ("iommu/amd: Print extended features in one line to fix divergent log levels")
Signed-off-by: Alexander Monakov <amonakov@...ras.ru>
Cc: Paul Menzel <pmenzel@...gen.mpg.de>
Cc: Joerg Roedel <jroedel@...e.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Cc: iommu@...ts.linux-foundation.org
---
 drivers/iommu/amd/init.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 596d0c413473..a25e241eff1c 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1929,8 +1929,11 @@ static void print_iommu_info(void)
 		pci_info(pdev, "Found IOMMU cap 0x%hx\n", iommu->cap_ptr);
 
 		if (iommu->cap & (1 << IOMMU_CAP_EFR)) {
-			pci_info(pdev, "Extended features (%#llx):",
+			pci_info(pdev, "Extended features (%#llx):\n",
 				 iommu->features);
+
+			pr_info("");
+
 			for (i = 0; i < ARRAY_SIZE(feat_str); ++i) {
 				if (iommu_feature(iommu, (1ULL << i)))
 					pr_cont(" %s", feat_str[i]);
-- 
2.30.0