[PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[Corcodel Marian]

 This patch not enable/disable bus mastering when is enabled on BIOS..
 pci_disable_device function also disable bus mastering for, disable bus mastering
  is dedicate function.

Signed-off-by: Corcodel Marian <asd@marian1000.go.ro>
---
 drivers/net/ethernet/realtek/r8169.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 02aec96..ec555e7 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -754,6 +754,7 @@ struct rtl8169_private {
 	struct timer_list timer;
 	u16 cp_cmd;
 	bool pcie;
+	bool bios_support;
 
 	u16 event_slow;
 
@@ -3718,13 +3719,27 @@ static void rtl8169_phy_timer(unsigned long __opaque)
 	rtl_schedule_task(tp, RTL_FLAG_TASK_PHY_PENDING);
 }
 
+static void rtl_disable_device (struct pci_dev *pdev)
+{
+	dev_WARN_ONCE(&pdev->dev, atomic_read(&pdev->enable_cnt) <= 0,
+		"disabling already-disabled device");
+
+	if (atomic_dec_return(&pdev->enable_cnt) != 0)
+		return;
+}
+
 static void rtl8169_release_board(struct pci_dev *pdev, struct net_device *dev,
 				  void __iomem *ioaddr)
 {
+	struct rtl8169_private *tp = netdev_priv(dev);
+
 	iounmap(ioaddr);
 	pci_release_regions(pdev);
 	pci_clear_mwi(pdev);
-	pci_disable_device(pdev);
+	if (!tp->bios_support)
+		pci_disable_device(pdev);
+	else
+		rtl_disable_device(pdev);
 	free_netdev(dev);
 }
 
@@ -6779,7 +6794,8 @@ static void rtl_wol_shutdown_quirk(struct rtl8169_private *tp)
 	case RTL_GIGA_MAC_VER_11:
 	case RTL_GIGA_MAC_VER_12:
 	case RTL_GIGA_MAC_VER_17:
-		pci_clear_master(tp->pci_dev);
+		if (!tp->bios_support)
+			pci_clear_master(tp->pci_dev);
 
 		RTL_W8(ChipCmd, CmdRxEnb);
 		/* PCI commit */
@@ -6996,6 +7012,7 @@ rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	void __iomem *ioaddr;
 	int chipset, i;
 	int rc;
+	u16 cmd;
 
 	if (netif_msg_drv(&debug)) {
 		printk(KERN_INFO "%s Gigabit Ethernet driver %s loaded\n",
@@ -7103,7 +7120,13 @@ rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	rtl_ack_events(tp, 0xffff);
 
-	pci_set_master(pdev);
+	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+	if (cmd & PCI_COMMAND_MASTER)
+		tp->bios_support = true;
+	else {
+		tp->bios_support = false;
+		pci_set_master(pdev);
+	}
 
 	/*
 	 * Pretend we are using VLANs; This bypasses a nasty bug where
-- 
2.1.4

Re: [PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[Francois Romieu]

Corcodel Marian <asd@marian1000.go.ro> :
>  This patch not enable/disable bus mastering when is enabled on BIOS..

It bloats the driver without any benefit.

-- 
Ueimor

Re: [PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[Corcodel Marian]

On Sat, 12 Mar 2016 10:44:01 +0100
Francois Romieu <romieu@fr.zoreil.com> wrote:

> Corcodel Marian <asd@marian1000.go.ro> :
> >  This patch not enable/disable bus mastering when is enabled on
> > BIOS..
> 
> It bloats the driver without any benefit.
> 

For mee this patch is very important , decrease time to autonegociation
and start nic on full speed alltimes.

Re: [PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[Francois Romieu]

Corcodel Marian <asd@marian1000.go.ro> :
[...]
> For mee this patch is very important , decrease time to autonegociation
> and start nic on full speed alltimes.

Really ? The commit message did not tell much about it.

How much did time decrease ? How did you measure it ? 

Against which chipset(s) ?

On which motherboard ?

How does it behave on current kernel ?

How many different patches are you testing at the same time ?

Who was able to reproduce it ?

How do you explain it ?

-- 
Ueimor

Re: [PATCH net v3.16]r8169: Not enable/disable bus mastering when is enabled on BIOS

[Sergei Shtylyov]

Hello.

On 03/12/2016 09:33 AM, Corcodel Marian wrote:

>   This patch not enable/disable bus mastering when is enabled on BIOS..
>   pci_disable_device function also disable bus mastering for, disable bus mastering
>    is dedicate function.
>
> Signed-off-by: Corcodel Marian <asd@marian1000.go.ro>
> ---
>   drivers/net/ethernet/realtek/r8169.c | 29 ++++++++++++++++++++++++++---
>   1 file changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
> index 02aec96..ec555e7 100644
> --- a/drivers/net/ethernet/realtek/r8169.c
> +++ b/drivers/net/ethernet/realtek/r8169.c
[...]
> @@ -7103,7 +7120,13 @@ rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
>
>   	rtl_ack_events(tp, 0xffff);
>
> -	pci_set_master(pdev);
> +	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> +	if (cmd & PCI_COMMAND_MASTER)
> +		tp->bios_support = true;
> +	else {

    Documentation/CodingStyle requites {} on all branches of the *if* 
statement if at least one branch has them.

> +		tp->bios_support = false;
> +		pci_set_master(pdev);
> +	}
>
>   	/*
>   	 * Pretend we are using VLANs; This bypasses a nasty bug where

MBR, Sergei