From: Koen Vandeputte <koen.vandeputte@ncentric.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-pci@vger.kernel.org,
Koen Vandeputte <koen.vandeputte@ncentric.com>,
Arnd Bergmann <arnd@arndb.de>, Krzysztof Halasa <khalasa@piap.pl>,
Olof Johansson <olof@lixom.net>,
Robin Leblon <robin.leblon@ncentric.com>,
Rob Herring <robh@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Tim Harvey <tharvey@gateworks.com>,
stable@vger.kernel.org
Subject: [PATCH v2 2/2] arm: cns3xxx: use actual size reads for PCIe
Date: Mon, 7 Jan 2019 14:45:10 +0100 [thread overview]
Message-ID: <20190107134510.32494-2-koen.vandeputte@ncentric.com> (raw)
In-Reply-To: <20190107134510.32494-1-koen.vandeputte@ncentric.com>
commit 802b7c06adc7 ("ARM: cns3xxx: Convert PCI to use generic config accessors")
reimplemented cns3xxx_pci_read_config() using pci_generic_config_read32(),
which preserved the property of only doing 32-bit reads.
It also replaced cns3xxx_pci_write_config() with pci_generic_config_write(),
so it changed writes from always being 32 bits to being the actual size,
which works just fine.
Due to:
- The documentation does not mention that only 32 bit access is allowed.
- Writes are already executed using the actual size
- Extensive testing shows that 8b, 16b and 32b reads work as intended
It makes perfectly sense to also swap 32 bit reading in favor of actual size.
Fixes: 802b7c06adc7 ("ARM: cns3xxx: Convert PCI to use generic config accessors")
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Krzysztof Halasa <khalasa@piap.pl>
CC: Olof Johansson <olof@lixom.net>
CC: Robin Leblon <robin.leblon@ncentric.com>
CC: Rob Herring <robh@kernel.org>
CC: Russell King <linux@armlinux.org.uk>
CC: Tim Harvey <tharvey@gateworks.com>
CC: stable@vger.kernel.org # v4.0+
---
arch/arm/mach-cns3xxx/pcie.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/mach-cns3xxx/pcie.c b/arch/arm/mach-cns3xxx/pcie.c
index 5e11ad3164e0..95a11d5b3587 100644
--- a/arch/arm/mach-cns3xxx/pcie.c
+++ b/arch/arm/mach-cns3xxx/pcie.c
@@ -93,7 +93,7 @@ static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
u32 mask = (0x1ull << (size * 8)) - 1;
int shift = (where % 4) * 8;
- ret = pci_generic_config_read32(bus, devfn, where, size, val);
+ ret = pci_generic_config_read(bus, devfn, where, size, val);
if (ret == PCIBIOS_SUCCESSFUL && !bus->number && !devfn &&
(where & 0xffc) == PCI_CLASS_REVISION)
--
2.17.1
next prev parent reply other threads:[~2019-01-07 13:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-07 13:45 [PATCH v2 1/2] arm: cns3xxx: fix writing to wrong PCI registers after alignment Koen Vandeputte
2019-01-07 13:45 ` Koen Vandeputte [this message]
2019-01-08 6:10 ` [PATCH v2 2/2] arm: cns3xxx: use actual size reads for PCIe Krzysztof Hałasa
2019-01-25 10:55 ` Krzysztof Hałasa
2019-01-24 11:56 ` [PATCH v2 1/2] arm: cns3xxx: fix writing to wrong PCI registers after alignment Lorenzo Pieralisi
2019-01-24 15:23 ` Koen Vandeputte
2019-01-24 16:27 ` Lorenzo Pieralisi
2019-01-30 22:08 ` Arnd Bergmann
2019-01-30 23:06 ` Bjorn Helgaas
2019-01-31 8:00 ` Arnd Bergmann
2019-01-31 21:16 ` Bjorn Helgaas
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