@@ -152,6 +152,7 @@ struct tegra_dma_sg_req {
bool last_sg;
struct list_head node;
struct tegra_dma_desc *dma_desc;
+ unsigned int words_xferred;
};
/*
@@ -496,6 +497,7 @@ static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
nsg_req->configured = true;
+ nsg_req->words_xferred = 0;
tegra_dma_resume(tdc);
}
@@ -511,6 +513,7 @@ static void tdc_start_head_req(struct tegra_dma_channel *tdc)
typeof(*sg_req), node);
tegra_dma_start(tdc, sg_req);
sg_req->configured = true;
+ sg_req->words_xferred = 0;
tdc->busy = true;
}
@@ -638,6 +641,8 @@ static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
dma_desc->cb_count++;
+ sgreq->words_xferred = 0;
+
/* If not last req then put at end of pending list */
if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
list_move_tail(&sgreq->node, &tdc->pending_sg_req);
@@ -797,6 +802,65 @@ static int tegra_dma_terminate_all(struct dma_chan *dc)
return 0;
}
+static unsigned int tegra_dma_sg_bytes_xferred(struct tegra_dma_channel *tdc,
+ struct tegra_dma_sg_req *sg_req)
+{
+ unsigned long status, wcount = 0;
+
+ if (!list_is_first(&sg_req->node, &tdc->pending_sg_req))
+ return 0;
+
+ if (tdc->tdma->chip_data->support_separate_wcount_reg)
+ wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
+
+ status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
+
+ if (!tdc->tdma->chip_data->support_separate_wcount_reg)
+ wcount = status;
+
+ if (status & TEGRA_APBDMA_STATUS_ISE_EOC)
+ return sg_req->req_len;
+
+ wcount = get_current_xferred_count(tdc, sg_req, wcount);
+
+ if (!wcount) {
+ /*
+ * If wcount wasn't ever polled for this SG before, then
+ * simply assume that transfer hasn't started yet.
+ *
+ * Otherwise it's the end of the transfer.
+ *
+ * The alternative would be to poll the status register
+ * until EOC bit is set or wcount goes UP. That's so
+ * because EOC bit is getting set only after the last
+ * burst's completion and counter is less than the actual
+ * transfer size by 4 bytes. The counter value wraps around
+ * in a cyclic mode before EOC is set(!), so we can't easily
+ * distinguish start of transfer from its end.
+ */
+ if (sg_req->words_xferred)
+ wcount = sg_req->req_len - 4;
+
+ } else if (wcount < sg_req->words_xferred) {
+ /*
+ * This case will never happen for a non-cyclic transfer.
+ *
+ * For a cyclic transfer, although it is possible for the
+ * next transfer to have already started (resetting the word
+ * count), this case should still not happen because we should
+ * have detected that the EOC bit is set and hence the transfer
+ * was completed.
+ */
+ WARN_ON_ONCE(1);
+
+ wcount = sg_req->req_len - 4;
+ } else {
+ sg_req->words_xferred = wcount;
+ }
+
+ return wcount;
+}
+
static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
dma_cookie_t cookie, struct dma_tx_state *txstate)
{
@@ -806,6 +870,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
enum dma_status ret;
unsigned long flags;
unsigned int residual;
+ unsigned int bytes = 0;
ret = dma_cookie_status(dc, cookie, txstate);
if (ret == DMA_COMPLETE)
@@ -825,6 +890,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
dma_desc = sg_req->dma_desc;
if (dma_desc->txd.cookie == cookie) {
+ bytes = tegra_dma_sg_bytes_xferred(tdc, sg_req);
ret = dma_desc->dma_status;
goto found;
}
@@ -836,7 +902,7 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
found:
if (dma_desc && txstate) {
residual = dma_desc->bytes_requested -
- (dma_desc->bytes_transferred %
+ ((dma_desc->bytes_transferred + bytes) %
dma_desc->bytes_requested);
dma_set_residue(txstate, residual);
}
@@ -1441,12 +1507,7 @@ static int tegra_dma_probe(struct platform_device *pdev)
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
- /*
- * XXX The hardware appears to support
- * DMA_RESIDUE_GRANULARITY_BURST-level reporting, but it's
- * only used by this driver during tegra_dma_terminate_all()
- */
- tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+ tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
tdma->dma_dev.device_config = tegra_dma_slave_config;
tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
tdma->dma_dev.device_tx_status = tegra_dma_tx_status;