From: Pravin M. Bathija Date: Fri, 14 Mar 2008 09:52:28 +0000 (+0100) Subject: NEWEMAC: fix support for pause packets X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4373c9327f10c362f13d5b78557f93a471211a42;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git NEWEMAC: fix support for pause packets Problem Description and Fix --------------------------- When a pause packet(with destination as reserved Multicast address) is received by the EMAC hardware to control the flow of frames being transmitted by it, it is dropped by the hardware unless the reserved Multicast address is hashed in to the GAHT[1-4] registers. This code fix adds the default reserved multicast address to the GAHT[1-4] registers in the EMAC(s) present on the chip. The flow control with Pause packets will only work if the following register bits are programmed in EMAC: EMACx_MR1[APP] = 1 EMACx_RMR[BAE] = 1 EMACx_RMR[MAE] = 1 Behavior that may be observed in a running system ------------------------------------------------- A host transferring data from a PPC based system may send a Pause packet to the PPC EMAC requesting it to slow down the flow of packets. If the default reserved multicast MAC address is not programmed into the GAHT[1-4] registers this Pause packet will be dropped by PPC EMAC and no Flow Control will be done. Signed-off-by: Pravin M. Bathija Signed-off-by: Stefan Roese Signed-off-by: Jeff Garzik --- diff --git a/drivers/net/ibm_newemac/core.c b/drivers/net/ibm_newemac/core.c index e6c69f77259b..0789802d59ed 100644 --- a/drivers/net/ibm_newemac/core.c +++ b/drivers/net/ibm_newemac/core.c @@ -143,6 +143,10 @@ static inline void emac_report_timeout_error(struct emac_instance *dev, #define STOP_TIMEOUT_1000 13 #define STOP_TIMEOUT_1000_JUMBO 73 +static unsigned char default_mcast_addr[] = { + 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 +}; + /* Please, keep in sync with struct ibm_emac_stats/ibm_emac_error_stats */ static const char emac_stats_keys[EMAC_ETHTOOL_STATS_COUNT][ETH_GSTRING_LEN] = { "rx_packets", "rx_bytes", "tx_packets", "tx_bytes", "rx_packets_csum", @@ -618,6 +622,9 @@ static int emac_configure(struct emac_instance *dev) if (emac_phy_gpcs(dev->phy.mode)) emac_mii_reset_phy(&dev->phy); + /* Required for Pause packet support in EMAC */ + dev_mc_add(ndev, default_mcast_addr, sizeof(default_mcast_addr), 1); + return 0; }