From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: alchemy/gpr: au1000_eth regression with v2.6.37rc2 Date: Tue, 23 Nov 2010 16:01:37 +0100 Message-ID: <4CEBD751.7090807@grandegger.com> References: <4CE58593.50509@grandegger.com> <201011182330.08488.florian@openwrt.org> <4CE65199.7030007@grandegger.com> <201011191146.01454.florian@openwrt.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------080703020109020809040101" Cc: Linux-MIPS , Netdev@vger.kernel.org To: Florian Fainelli Return-path: In-Reply-To: <201011191146.01454.florian@openwrt.org> Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------080703020109020809040101 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Hi Florian, On 11/19/2010 11:46 AM, Florian Fainelli wrote: > Hello Wolfgang, > > On Friday 19 November 2010 11:29:45 Wolfgang Grandegger wrote: >> Hello Florian, >> >> On 11/18/2010 11:30 PM, Florian Fainelli wrote: >>> Hello Wolfgang, >>> >>> Le Thursday 18 November 2010 20:59:15, Wolfgang Grandegger a écrit : >>>> Hello, >>>> >>>> I just realized that the v2.6.37-rc2 kernel does not boot any more on >>>> the Alchemy GPR board. It works fine with v2.6.36. It hangs in the >>>> probe function of the au1000_eth driver when probing the second >>>> >>>> ethernet port (eth1): >>>> au1000_eth_mii: probed >>>> au1000-eth au1000-eth.0: (unregistered net_device): attached PHY >>>> driver >>>> >>>> [Generic PHY] (mii_bus:phy_addr=0:00, irq=-1) au1000-eth au1000-eth.0: >>>> eth0: Au1xx0 Ethernet found at 0x10500000, irq 35 au1000_eth: au1000_eth >>>> version 1.7 Pete Popov ... hangs ... >>>> >>>> Similar messages should follow for eth1. I narrowed down (bisect'ed) the >>>> >>>> problem to commit: >>>> commit d0e7cb5d401695809ba8c980124ab1d8c66efc8b >>>> Author: Florian Fainelli >>>> Date: Wed Sep 8 11:15:13 2010 +0000 >>>> >>>> au1000-eth: remove volatiles, switch to I/O accessors >>>> >>>> Remove all the volatile keywords where they were used, switch to >>>> using >>>> >>>> the proper readl/writel accessors. >>>> >>>> Signed-off-by: Florian Fainelli >>>> Signed-off-by: David S. Miller >>>> >>>> The kernel actually hangs when accessing "&aup->mac->mii_control" in >>>> au1000_mdio_read(), but only for eth1. Any idea what does go wrong? >>> >>> I do not understand so far while it hangs only for eth1. My device only >>> has one ethernet MAC, so I could not notice the problem. Looking at this >>> close, there are a couple of u32 const* usages in >>> au1000_mdio_{read,write} which are looking wrong to me now. Can you try >>> to remove these? >> >> That did not help. > > I suspected it, but thanks for the confirmation. > >> >>>> In principle, I do not want to access the MII regs of the MAC because >>>> eth0 and eth1 are connected to switches. But that's not possible, even >>>> with "aup->phy_static_config=1" and "aup->phy_addr=0". >>> >>> If you think this is another issue, I will fix it in another patch. >> >> Accessing the MII registers of the MAC should not hang the system even >> if I do not need to. First I want to understand why. Looks like a wired >> optimizer issue. > > I definitively agree, furthermore since there is a timeout for read and write > operations. I will look at the assembly and see if I can see anything > different. The attached patch fixes the issue. It's caused by a simple porting error. I'm going to prepare a proper patch later today. Wolfgang. --------------080703020109020809040101 Content-Type: text/x-diff; name="au1000-eth-mac-enable.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="au1000-eth-mac-enable.patch" diff --git a/drivers/net/au1000_eth.c b/drivers/net/au1000_eth.c index 43489f8..53eff9b 100644 --- a/drivers/net/au1000_eth.c +++ b/drivers/net/au1000_eth.c @@ -155,10 +155,10 @@ static void au1000_enable_mac(struct net_device *dev, int force_reset) spin_lock_irqsave(&aup->lock, flags); if (force_reset || (!aup->mac_enabled)) { - writel(MAC_EN_CLOCK_ENABLE, &aup->enable); + writel(MAC_EN_CLOCK_ENABLE, aup->enable); au_sync_delay(2); writel((MAC_EN_RESET0 | MAC_EN_RESET1 | MAC_EN_RESET2 - | MAC_EN_CLOCK_ENABLE), &aup->enable); + | MAC_EN_CLOCK_ENABLE), aup->enable); au_sync_delay(2); aup->mac_enabled = 1; @@ -503,9 +503,9 @@ static void au1000_reset_mac_unlocked(struct net_device *dev) au1000_hard_stop(dev); - writel(MAC_EN_CLOCK_ENABLE, &aup->enable); + writel(MAC_EN_CLOCK_ENABLE, aup->enable); au_sync_delay(2); - writel(0, &aup->enable); + writel(0, aup->enable); au_sync_delay(2); aup->tx_full = 0; @@ -1119,7 +1119,7 @@ static int __devinit au1000_probe(struct platform_device *pdev) /* set a random MAC now in case platform_data doesn't provide one */ random_ether_addr(dev->dev_addr); - writel(0, &aup->enable); + writel(0, aup->enable); aup->mac_enabled = 0; pd = pdev->dev.platform_data; --------------080703020109020809040101--