@@ -1277,6 +1277,7 @@ static int cpsw_ndo_open(struct net_device *ndev)
if (!cpsw_common_res_usage_state(priv)) {
struct cpsw_priv *priv_sl0 = cpsw_get_slave_priv(priv, 0);
+ int buf_num;
/* setup tx dma to fixed prio and zero offset */
cpdma_control_set(priv->dma, CPDMA_TX_PRIO_FIXED, 1);
@@ -1304,10 +1305,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
enable_irq(priv->irqs_table[0]);
}
- if (WARN_ON(!priv->data.rx_descs))
- priv->data.rx_descs = 128;
-
- for (i = 0; i < priv->data.rx_descs; i++) {
+ buf_num = cpdma_chan_get_rx_buf_num(priv->dma);
+ for (i = 0; i < buf_num; i++) {
struct sk_buff *skb;
ret = -ENOMEM;
@@ -1998,12 +1997,6 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
}
data->bd_ram_size = prop;
- if (of_property_read_u32(node, "rx_descs", &prop)) {
- dev_err(&pdev->dev, "Missing rx_descs property in the DT.\n");
- return -EINVAL;
- }
- data->rx_descs = prop;
-
if (of_property_read_u32(node, "mac_control", &prop)) {
dev_err(&pdev->dev, "Missing mac_control property in the DT.\n");
return -EINVAL;
@@ -35,7 +35,6 @@ struct cpsw_platform_data {
u32 cpts_clock_shift; /* convert input clock ticks to nanoseconds */
u32 ale_entries; /* ale table size */
u32 bd_ram_size; /*buffer descriptor ram size */
- u32 rx_descs; /* Number of Rx Descriptios */
u32 mac_control; /* Mac control register */
u16 default_vlan; /* Def VLAN for ALE lookup in VLAN aware mode*/
bool dual_emac; /* Enable Dual EMAC mode */
@@ -543,6 +543,12 @@ struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
}
EXPORT_SYMBOL_GPL(cpdma_chan_create);
+int cpdma_chan_get_rx_buf_num(struct cpdma_ctlr *ctlr)
+{
+ return ctlr->pool->num_desc / 2;
+}
+EXPORT_SYMBOL_GPL(cpdma_chan_get_rx_buf_num);
+
int cpdma_chan_destroy(struct cpdma_chan *chan)
{
struct cpdma_ctlr *ctlr;
@@ -81,6 +81,7 @@ int cpdma_ctlr_dump(struct cpdma_ctlr *ctlr);
struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
cpdma_handler_fn handler);
+int cpdma_chan_get_rx_buf_num(struct cpdma_ctlr *ctlr);
int cpdma_chan_destroy(struct cpdma_chan *chan);
int cpdma_chan_start(struct cpdma_chan *chan);
int cpdma_chan_stop(struct cpdma_chan *chan);
There is no reason in rx_descs property because davinici_cpdma driver splits pool of descriptors equally between tx and rx channels. That is, if number of descriptors 256, 128 of them are for rx channels. While receiving, the descriptor is freed to the pool and then allocated with new skb. And if in DT the "rx_descs" is set to 64, then 128 - 64 = 64 descriptors are always in the pool and cannot be used, for tx, for instance. It's not correct resource usage, better to set it to half of pool, then the rx pool can be used in full. It will not have any impact on performance, as anyway, the "redundant" descriptors were unused. Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org> --- drivers/net/ethernet/ti/cpsw.c | 13 +++---------- drivers/net/ethernet/ti/cpsw.h | 1 - drivers/net/ethernet/ti/davinci_cpdma.c | 6 ++++++ drivers/net/ethernet/ti/davinci_cpdma.h | 1 + 4 files changed, 10 insertions(+), 11 deletions(-)