[PATCH net-next v4 1/2] r8169: Don't disable ASPM in the driver

[PATCH net-next v4 1/2] r8169: Don't disable ASPM in the driver

[Kai-Heng Feng]

Enable or disable ASPM should be done in PCI core instead of in the
device driver.

Commit ba04c7c93bbc ("r8169: disable ASPM") uses
pci_disable_link_state() to disable ASPM, but it's not the best way to
do it. If the device really wants to disable ASPM, we can use a quirk in
PCI core to prevent the PCI core from setting ASPM before probe.

Let's remove pci_disable_link_state() for now. Use PCI core quirks if
any regression happens.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v4:
- Improve commit message.
- Move the empty line to where it belongs.

v3:
- Change commit message wording.
- Rename the function to rtl_hw_aspm_clkreq_enable().

v2:
- Remove module parameter.
- Remove pci_disable_link_state().

 drivers/net/ethernet/realtek/r8169.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 75dfac0248f4..2bdfd25acd58 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -25,7 +25,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/pm_runtime.h>
 #include <linux/firmware.h>
-#include <linux/pci-aspm.h>
 #include <linux/prefetch.h>
 #include <linux/ipv6.h>
 #include <net/ip6_checksum.h>
@@ -7647,11 +7646,6 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	mii->reg_num_mask = 0x1f;
 	mii->supports_gmii = cfg->has_gmii;
 
-	/* disable ASPM completely as that cause random device stop working
-	 * problems as well as full system hangs for some PCIe devices users */
-	pci_disable_link_state(pdev, PCIE_LINK_STATE_L0S | PCIE_LINK_STATE_L1 |
-				     PCIE_LINK_STATE_CLKPM);
-
 	/* enable device (incl. PCI PM wakeup and hotplug setup) */
 	rc = pcim_enable_device(pdev);
 	if (rc < 0) {
-- 
2.17.0

[PATCH net-next v4 2/2] r8169: Reinstate ASPM Support

[Kai-Heng Feng]

On Intel platforms (Skylake and newer), ASPM support in r8169 is the
last missing puzzle to let CPU's Package C-State reaches PC8.  Without
ASPM support, the CPU cannot reach beyond PC3. PC8 can save additional
~3W in comparison with PC3 on a Coffee Lake platform, Dell G3 3779.

This is based on the work from Chunhao Lin <hau@realtek.com>.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v4:
- Improve commit message.
- Move the empty line to where it belongs.

v3:
- Change commit message wording.
- Rename the function to rtl_hw_aspm_clkreq_enable().

v2:
- Remove module parameter.
- Remove pci_disable_link_state().

 drivers/net/ethernet/realtek/r8169.c | 39 +++++++++++++++++++---------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 2bdfd25acd58..269ac7561368 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -5289,6 +5289,17 @@ static void rtl_pcie_state_l2l3_enable(struct rtl8169_private *tp, bool enable)
 	RTL_W8(tp, Config3, data);
 }
 
+static void rtl_hw_aspm_clkreq_enable(struct rtl8169_private *tp, bool enable)
+{
+	if (enable) {
+		RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
+		RTL_W8(tp, Config5, RTL_R8(tp, Config5) | ASPM_en);
+	} else {
+		RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
+		RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	}
+}
+
 static void rtl_hw_start_8168bb(struct rtl8169_private *tp)
 {
 	RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Beacon_en);
@@ -5645,9 +5656,9 @@ static void rtl_hw_start_8168g_1(struct rtl8169_private *tp)
 	rtl_hw_start_8168g(tp);
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168g_1, ARRAY_SIZE(e_info_8168g_1));
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168g_2(struct rtl8169_private *tp)
@@ -5680,9 +5691,9 @@ static void rtl_hw_start_8411_2(struct rtl8169_private *tp)
 	rtl_hw_start_8168g(tp);
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8411_2, ARRAY_SIZE(e_info_8411_2));
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168h_1(struct rtl8169_private *tp)
@@ -5699,8 +5710,7 @@ static void rtl_hw_start_8168h_1(struct rtl8169_private *tp)
 	};
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168h_1, ARRAY_SIZE(e_info_8168h_1));
 
 	RTL_W32(tp, TxConfig, RTL_R32(tp, TxConfig) | TXCFG_AUTO_FIFO);
@@ -5779,6 +5789,8 @@ static void rtl_hw_start_8168h_1(struct rtl8169_private *tp)
 	r8168_mac_ocp_write(tp, 0xe63e, 0x0000);
 	r8168_mac_ocp_write(tp, 0xc094, 0x0000);
 	r8168_mac_ocp_write(tp, 0xc09e, 0x0000);
+
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168ep(struct rtl8169_private *tp)
@@ -5830,11 +5842,12 @@ static void rtl_hw_start_8168ep_1(struct rtl8169_private *tp)
 	};
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168ep_1, ARRAY_SIZE(e_info_8168ep_1));
 
 	rtl_hw_start_8168ep(tp);
+
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168ep_2(struct rtl8169_private *tp)
@@ -5846,14 +5859,15 @@ static void rtl_hw_start_8168ep_2(struct rtl8169_private *tp)
 	};
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168ep_2, ARRAY_SIZE(e_info_8168ep_2));
 
 	rtl_hw_start_8168ep(tp);
 
 	RTL_W8(tp, DLLPR, RTL_R8(tp, DLLPR) & ~PFM_EN);
 	RTL_W8(tp, MISC_1, RTL_R8(tp, MISC_1) & ~PFM_D3COLD_EN);
+
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168ep_3(struct rtl8169_private *tp)
@@ -5867,8 +5881,7 @@ static void rtl_hw_start_8168ep_3(struct rtl8169_private *tp)
 	};
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168ep_3, ARRAY_SIZE(e_info_8168ep_3));
 
 	rtl_hw_start_8168ep(tp);
@@ -5888,6 +5901,8 @@ static void rtl_hw_start_8168ep_3(struct rtl8169_private *tp)
 	data = r8168_mac_ocp_read(tp, 0xe860);
 	data |= 0x0080;
 	r8168_mac_ocp_write(tp, 0xe860, data);
+
+	rtl_hw_aspm_clkreq_enable(tp, true);
 }
 
 static void rtl_hw_start_8168(struct rtl8169_private *tp)
-- 
2.17.0

Re: [PATCH net-next v4 2/2] r8169: Reinstate ASPM Support

[David Miller]

From: Kai-Heng Feng <kai.heng.feng@canonical.com>
Date: Thu, 21 Jun 2018 16:30:39 +0800

> On Intel platforms (Skylake and newer), ASPM support in r8169 is the
> last missing puzzle to let CPU's Package C-State reaches PC8.  Without
> ASPM support, the CPU cannot reach beyond PC3. PC8 can save additional
> ~3W in comparison with PC3 on a Coffee Lake platform, Dell G3 3779.
> 
> This is based on the work from Chunhao Lin <hau@realtek.com>.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Also applied.

Thank you for being so persistent.

Re: [PATCH net-next v4 1/2] r8169: Don't disable ASPM in the driver

[David Miller]

From: Kai-Heng Feng <kai.heng.feng@canonical.com>
Date: Thu, 21 Jun 2018 16:30:38 +0800

> Enable or disable ASPM should be done in PCI core instead of in the
> device driver.
> 
> Commit ba04c7c93bbc ("r8169: disable ASPM") uses
> pci_disable_link_state() to disable ASPM, but it's not the best way to
> do it. If the device really wants to disable ASPM, we can use a quirk in
> PCI core to prevent the PCI core from setting ASPM before probe.
> 
> Let's remove pci_disable_link_state() for now. Use PCI core quirks if
> any regression happens.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Applied.