| Message ID | 20240918193452.417115-1-shenwei.wang@nxp.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [v2,net] net: stmmac: dwmac4: extend timeout for VLAN Tag register busy bit check | expand |
On Wed, Sep 18, 2024 at 02:34:52PM -0500, Shenwei Wang wrote: > Increase the timeout for checking the busy bit of the VLAN Tag register > from 10µs to 500ms. This change is necessary to accommodate scenarios > where Energy Efficient Ethernet (EEE) is enabled. > > Overnight testing revealed that when EEE is active, the busy bit can > remain set for up to approximately 300ms. The new 500ms timeout provides > a safety margin. Do you know what EEE has to do with VLAN filtering? Could there be other registers which suffer from the same problem? Andrew
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c index a1858f083eef..a0cfa2eaebb4 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c @@ -14,6 +14,7 @@ #include <linux/slab.h> #include <linux/ethtool.h> #include <linux/io.h> +#include <linux/iopoll.h> #include "stmmac.h" #include "stmmac_pcs.h" #include "dwmac4.h" @@ -471,7 +472,7 @@ static int dwmac4_write_vlan_filter(struct net_device *dev, u8 index, u32 data) { void __iomem *ioaddr = (void __iomem *)dev->base_addr; - int i, timeout = 10; + int ret, timeout = 500000; //500ms u32 val; if (index >= hw->num_vlan) @@ -487,12 +488,11 @@ static int dwmac4_write_vlan_filter(struct net_device *dev, writel(val, ioaddr + GMAC_VLAN_TAG); - for (i = 0; i < timeout; i++) { - val = readl(ioaddr + GMAC_VLAN_TAG); - if (!(val & GMAC_VLAN_TAG_CTRL_OB)) - return 0; - udelay(1); - } + ret = readl_poll_timeout(ioaddr + GMAC_VLAN_TAG, val, + !(val & GMAC_VLAN_TAG_CTRL_OB), + 1000, timeout); + if (!ret) + return 0; netdev_err(dev, "Timeout accessing MAC_VLAN_Tag_Filter\n");
Increase the timeout for checking the busy bit of the VLAN Tag register from 10µs to 500ms. This change is necessary to accommodate scenarios where Energy Efficient Ethernet (EEE) is enabled. Overnight testing revealed that when EEE is active, the busy bit can remain set for up to approximately 300ms. The new 500ms timeout provides a safety margin. Fixes: ed64639bc1e0 ("net: stmmac: Add support for VLAN Rx filtering") Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com> --- Changes in v2: - replace the udelay with readl_poll_timeout per Simon's review. --- drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) -- 2.34.1