KumiSystems/openwrtv3
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

mvebu: reduce speed to gen1 for espressobin pcie

Browse source 
Since the beginning there's been an issue with initializing the Atheros
based MiniPCIe wireless cards. Here's an example of kerenel log:

 OF: PCI: host bridge /soc/pcie@d0070000 ranges:
 OF: PCI:   MEM 0xe8000000..0xe8ffffff -> 0xe8000000
 OF: PCI:    IO 0xe9000000..0xe900ffff -> 0xe9000000
 advk-pcie d0070000.pcie: link up
 advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00
 pci_bus 0000:00: root bus resource [bus 00-ff]
 pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff]
 pci_bus 0000:00: root bus resource [io  0x0000-0xffff](bus address[0xe9000000-0xe900ffff])
 pci 0000:00:00.0: BAR 0: assigned [mem0xe8000000-0xe801ffff 64bit]
 pci 0000:00:00.0: BAR 6: assigned [mem0xe8020000-0xe802ffff pref]
 [...]
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x44
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
 ath9k 0000:00:00.0: enabling device (0000 -> 0002)
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0xc
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x40
 ath9k 0000:00:00.0: request_irq failed
 advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
 ath9k: probe of 0000:00:00.0 failed with error -22

The same happens for ath5k cards, while ath10k card didn't appear at
all (not detected):

 OF: PCI: host bridge /soc/pcie@d0070000 ranges:
 OF: PCI:   MEM 0xe8000000..0xe8ffffff -> 0xe8000000
 OF: PCI:    IO 0xe9000000..0xe900ffff -> 0xe9000000
 advk-pcie d0070000.pcie: link never came up
 advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00
 pci_bus 0000:00: root bus resource [bus 00-ff]
 pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff]
 pci_bus 0000:00: root bus resource [io  0x0000-0xffff](bus address[0xe9000000-0xe900ffff])
 advk-pcie d0070000.pcie: config read/write timed out

Following the issue on esppressobin.net forum [1] the workaround seems
to be limiting the speed of PCIe bridge to 1st generation. This fixed
the initialisation of all tested Atheros wireless cards.

The change shouldn't affect the performance for wireless cards,
it could reduce the performance of storage controller cards but since
OpenWrt focuses on wireless connectivity, fixing compatibility with
wireless cards should be a priority.

For the record, the iwlwifi and mt76 cards were not affected by this
issue.

1. http://espressobin.net/forums/topic/which-pcie-wlan-cards-are-supported

Signed-off-by: Tomasz Maciej Nowak <tomek_n@o2.pl>
This commit is contained in:
Tomasz Maciej Nowak 2018-06-14 21:15:59 +02:00 committed by John Crispin
parent 4ec8c8c23e
commit 772258044b
2 changed files with 116 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

43
target/linux/mvebu/patches-4.14/527-PCI-aardvark-allow-to-specify-link-capability.patch Normal file
View file

@ -0,0 +1,43 @@
From f70b629e488cc3f2a325ac35476f4f7ae502c5d0 Mon Sep 17 00:00:00 2001
From: Tomasz Maciej Nowak <tmn505@gmail.com>
Date: Thu, 14 Jun 2018 14:24:40 +0200
Subject: [PATCH 1/2] PCI: aardvark: allow to specify link capability
Use DT of_pci_get_max_link_speed() facility to allow specifying link
capability. If none or unspecified value is given it falls back to gen2,
which is default for Armada 3700 SoC.
Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>
---
drivers/pci/host/pci-aardvark.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
--- a/drivers/pci/host/pci-aardvark.c
+++ b/drivers/pci/host/pci-aardvark.c
@@ -272,6 +272,8 @@ static void advk_pcie_set_ob_win(struct
static void advk_pcie_setup_hw(struct advk_pcie *pcie)
{
+ struct device *dev = &pcie->pdev->dev;
+ struct device_node *node = dev->of_node;
u32 reg;
int i;
@@ -311,10 +313,15 @@ static void advk_pcie_setup_hw(struct ad
PCIE_CORE_CTRL2_TD_ENABLE;
advk_writel(pcie, reg, PCIE_CORE_CTRL2_REG);
- /* Set GEN2 */
+ /* Set GEN */
reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG);
reg &= ~PCIE_GEN_SEL_MSK;
- reg |= SPEED_GEN_2;
+ if (of_pci_get_max_link_speed(node) == 1)
+ reg |= SPEED_GEN_1;
+ else if (of_pci_get_max_link_speed(node) == 3)
+ reg |= SPEED_GEN_3;
+ else
+ reg |= SPEED_GEN_2;
advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG);
/* Set lane X1 */

73
target/linux/mvebu/patches-4.14/528-arm64-dts-armada-3720-espressobin-set-max-link-to-ge.patch Normal file
View file

@ -0,0 +1,73 @@
From 33f8fdcedb01680427328d710594facef7a0092c Mon Sep 17 00:00:00 2001
From: Tomasz Maciej Nowak <tmn505@gmail.com>
Date: Thu, 14 Jun 2018 14:40:26 +0200
Subject: [PATCH 2/2] arm64: dts: armada-3720-espressobin: set max link to gen1
Since the beginning there's been an issue with initializing the Atheros
based MiniPCIe wireless cards. Here's an example of kerenel log:
OF: PCI: host bridge /soc/pcie@d0070000 ranges:
OF: PCI: MEM 0xe8000000..0xe8ffffff -> 0xe8000000
OF: PCI: IO 0xe9000000..0xe900ffff -> 0xe9000000
advk-pcie d0070000.pcie: link up
advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [bus 00-ff]
pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff]
pci_bus 0000:00: root bus resource [io 0x0000-0xffff](bus address [0xe9000000-0xe900ffff])
pci 0000:00:00.0: BAR 0: assigned [mem0xe8000000-0xe801ffff 64bit]
pci 0000:00:00.0: BAR 6: assigned [mem0xe8020000-0xe802ffff pref]
[...]
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x44
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
ath9k 0000:00:00.0: enabling device (0000 -> 0002)
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x3c
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0xc
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x40
ath9k 0000:00:00.0: request_irq failed
advk-pcie d0070000.pcie: Posted PIO Response Status: CA,0xe00 @ 0x4
ath9k: probe of 0000:00:00.0 failed with error -22
The same happens for ath5k cards, while ath10k card didn't appear at
all (not detected):
OF: PCI: host bridge /soc/pcie@d0070000 ranges:
OF: PCI: MEM 0xe8000000..0xe8ffffff -> 0xe8000000
OF: PCI: IO 0xe9000000..0xe900ffff -> 0xe9000000
advk-pcie d0070000.pcie: link never came up
advk-pcie d0070000.pcie: PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [bus 00-ff]
pci_bus 0000:00: root bus resource [mem0xe8000000-0xe8ffffff]
pci_bus 0000:00: root bus resource [io 0x0000-0xffff](bus address [0xe9000000-0xe900ffff])
advk-pcie d0070000.pcie: config read/write timed out
Following the issue on esppressobin.net forum [1] the workaround seems
to be limiting the speed of PCIe bridge to 1st generation. This fixed
the initialisation of all tested Atheros wireless cards.
The patch in the forum thread swaped registers which would limit speed
for all Armada 3700 based boards. The approach in this patch, in
conjunction with "PCI: aardvark: allow to specify link capability" patch
is less invasive, it only touches the affected board.
For the record, the iwlwifi and mt76 cards were not affected by this
issue.
1. http://espressobin.net/forums/topic/which-pcie-wlan-cards-are-supported
Signed-off-by: Tomasz Maciej Nowak <tmn505@gmail.com>
---
arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts | 2 ++
1 file changed, 2 insertions(+)
--- a/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts
+++ b/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts
@@ -79,6 +79,8 @@
/* J9 */
&pcie0 {
status = "okay";
+
+ max-link-speed = <1>;
};
/* J6 */