This is a note to let you know that I've just added the patch titled net: ethernet: ti: cpsw: adjust cpsw fifos depth for fullduplex flow control to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-ethernet-ti-cpsw-adjust-cpsw-fifos-depth-for-fullduplex-flow-control.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Apr 10 13:58:07 CEST 2018 From: Grygorii Strashko <grygorii.strashko@xxxxxx> Date: Mon, 8 May 2017 14:21:21 -0500 Subject: net: ethernet: ti: cpsw: adjust cpsw fifos depth for fullduplex flow control From: Grygorii Strashko <grygorii.strashko@xxxxxx> [ Upstream commit 48f5bccc60675f8426a6159935e8636a1fd89f56 ] When users set flow control using ethtool the bits are set properly in the CPGMAC_SL MACCONTROL register, but the FIFO depth in the respective Port n Maximum FIFO Blocks (Pn_MAX_BLKS) registers remains set to the minimum size reset value. When receive flow control is enabled on a port, the port's associated FIFO block allocation must be adjusted. The port RX allocation must increase to accommodate the flow control runout. The TRM recommends numbers of 5 or 6. Hence, apply required Port FIFO configuration to Pn_MAX_BLKS.Pn_TX_MAX_BLKS=0xF and Pn_MAX_BLKS.Pn_RX_MAX_BLKS=0x5 during interface initialization. Cc: Schuyler Patton <spatton@xxxxxx> Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/ti/cpsw.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) --- a/drivers/net/ethernet/ti/cpsw.c +++ b/drivers/net/ethernet/ti/cpsw.c @@ -293,6 +293,10 @@ struct cpsw_ss_regs { /* Bit definitions for the CPSW1_TS_SEQ_LTYPE register */ #define CPSW_V1_SEQ_ID_OFS_SHIFT 16 +#define CPSW_MAX_BLKS_TX 15 +#define CPSW_MAX_BLKS_TX_SHIFT 4 +#define CPSW_MAX_BLKS_RX 5 + struct cpsw_host_regs { u32 max_blks; u32 blk_cnt; @@ -1120,11 +1124,23 @@ static void cpsw_slave_open(struct cpsw_ switch (priv->version) { case CPSW_VERSION_1: slave_write(slave, TX_PRIORITY_MAPPING, CPSW1_TX_PRI_MAP); + /* Increase RX FIFO size to 5 for supporting fullduplex + * flow control mode + */ + slave_write(slave, + (CPSW_MAX_BLKS_TX << CPSW_MAX_BLKS_TX_SHIFT) | + CPSW_MAX_BLKS_RX, CPSW1_MAX_BLKS); break; case CPSW_VERSION_2: case CPSW_VERSION_3: case CPSW_VERSION_4: slave_write(slave, TX_PRIORITY_MAPPING, CPSW2_TX_PRI_MAP); + /* Increase RX FIFO size to 5 for supporting fullduplex + * flow control mode + */ + slave_write(slave, + (CPSW_MAX_BLKS_TX << CPSW_MAX_BLKS_TX_SHIFT) | + CPSW_MAX_BLKS_RX, CPSW2_MAX_BLKS); break; } Patches currently in stable-queue which might be from grygorii.strashko@xxxxxx are queue-3.18/net-ethernet-ti-cpsw-adjust-cpsw-fifos-depth-for-fullduplex-flow-control.patch