From 3f7832c26cc0cad2245981f777f3ee684399ce93 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Thu, 12 Oct 2017 12:42:04 -0500 Subject: [PATCH] Revert "net: qcom/emac: enforce DMA address restrictions" This reverts commit df1ec1b9d0df57e96011f175418dc95b1af46821. It turns out that memory allocated via dma_alloc_coherent is always aligned to the size of the buffer, so there's no way the RRD and RFD can ever be in separate 32-bit regions. Signed-off-by: Timur Tabi Signed-off-by: David S. Miller --- drivers/net/ethernet/qualcomm/emac/emac-mac.c | 39 +++++++++++---------------- 1 file changed, 15 insertions(+), 24 deletions(-) diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c b/drivers/net/ethernet/qualcomm/emac/emac-mac.c index 0f5ece5d9507..9cbb27263742 100644 --- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c +++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c @@ -734,11 +734,6 @@ static int emac_rx_descs_alloc(struct emac_adapter *adpt) rx_q->rrd.size = rx_q->rrd.count * (adpt->rrd_size * 4); rx_q->rfd.size = rx_q->rfd.count * (adpt->rfd_size * 4); - /* Check if the RRD and RFD are aligned properly, and if not, adjust. */ - if (upper_32_bits(ring_header->dma_addr) != - upper_32_bits(ring_header->dma_addr + ALIGN(rx_q->rrd.size, 8))) - ring_header->used = ALIGN(rx_q->rrd.size, 8); - rx_q->rrd.dma_addr = ring_header->dma_addr + ring_header->used; rx_q->rrd.v_addr = ring_header->v_addr + ring_header->used; ring_header->used += ALIGN(rx_q->rrd.size, 8); @@ -772,18 +767,11 @@ int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt) /* Ring DMA buffer. Each ring may need up to 8 bytes for alignment, * hence the additional padding bytes are allocated. - * - * Also double the memory allocated for the RRD so that we can - * re-align it if necessary. The EMAC has a restriction that the - * upper 32 bits of the base addresses for the RFD and RRD rings - * must be the same. It is extremely unlikely that this is not the - * case, since the rings are only a few KB in size. However, we - * need to check for this anyway, and if the two rings are not - * compliant, then we re-align. */ - ring_header->size = ALIGN(num_tx_descs * (adpt->tpd_size * 4), 8) + - ALIGN(num_rx_descs * (adpt->rfd_size * 4), 8) + - ALIGN(num_rx_descs * (adpt->rrd_size * 4), 8) * 2; + ring_header->size = num_tx_descs * (adpt->tpd_size * 4) + + num_rx_descs * (adpt->rfd_size * 4) + + num_rx_descs * (adpt->rrd_size * 4) + + 8 + 2 * 8; /* 8 byte per one Tx and two Rx rings */ ring_header->used = 0; ring_header->v_addr = dma_zalloc_coherent(dev, ring_header->size, @@ -792,23 +780,26 @@ int emac_mac_rx_tx_rings_alloc_all(struct emac_adapter *adpt) if (!ring_header->v_addr) return -ENOMEM; - ret = emac_rx_descs_alloc(adpt); - if (ret) { - netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n"); - goto err_alloc_rx; - } + ring_header->used = ALIGN(ring_header->dma_addr, 8) - + ring_header->dma_addr; ret = emac_tx_q_desc_alloc(adpt, &adpt->tx_q); if (ret) { - netdev_err(adpt->netdev, "transmit queue allocation failed\n"); + netdev_err(adpt->netdev, "error: Tx Queue alloc failed\n"); goto err_alloc_tx; } + ret = emac_rx_descs_alloc(adpt); + if (ret) { + netdev_err(adpt->netdev, "error: Rx Queue alloc failed\n"); + goto err_alloc_rx; + } + return 0; -err_alloc_tx: - emac_rx_q_bufs_free(adpt); err_alloc_rx: + emac_tx_q_bufs_free(adpt); +err_alloc_tx: dma_free_coherent(dev, ring_header->size, ring_header->v_addr, ring_header->dma_addr); -- 2.11.0