Octeontx2-af: fix pause frame configuration in GMP mode

The Octeontx2 MAC block (CGX) has separate data paths (SMU and GMP) for
different speeds, allowing for efficient data transfer.

The previous patch which added pause frame configuration has a bug due
to which pause frame feature is not working in GMP mode.

This patch fixes the issue by configurating appropriate registers.

Fixes: f7e086e ("octeontx2-af: Pause frame configuration at cgx")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240326052720.4441-1-hkelam@marvell.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Hariprasad Kelam

drivers/net/ethernet/marvell/octeontx2/af/cgx.c

@@ -808,6 +808,11 @@ static int cgx_lmac_enadis_pause_frm(void *cgxd, int lmac_id,
 	if (!is_lmac_valid(cgx, lmac_id))
 		return -ENODEV;
 
+	cfg = cgx_read(cgx, lmac_id, CGXX_GMP_GMI_RXX_FRM_CTL);
+	cfg &= ~CGX_GMP_GMI_RXX_FRM_CTL_CTL_BCK;
+	cfg |= rx_pause ? CGX_GMP_GMI_RXX_FRM_CTL_CTL_BCK : 0x0;
+	cgx_write(cgx, lmac_id, CGXX_GMP_GMI_RXX_FRM_CTL, cfg);
+
 	cfg = cgx_read(cgx, lmac_id, CGXX_SMUX_RX_FRM_CTL);
 	cfg &= ~CGX_SMUX_RX_FRM_CTL_CTL_BCK;
 	cfg |= rx_pause ? CGX_SMUX_RX_FRM_CTL_CTL_BCK : 0x0;