From: Peter Ujfalusi <peter.ujfalusi@ti.com>
To: <vkoul@kernel.org>
Cc: <dan.j.williams@intel.com>, <dmaengine@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-omap@vger.kernel.org>
Subject: [PATCH v4 2/3] dmaengine: ti: edma: Correct the residue calculation (fix for memcpy)
Date: Tue, 18 Jun 2019 16:21:47 +0300 [thread overview]
Message-ID: <20190618132148.26468-3-peter.ujfalusi@ti.com> (raw)
In-Reply-To: <20190618132148.26468-1-peter.ujfalusi@ti.com>
For memcpy we never stored the start address of the transfer for the pset
which rendered the memcpy residue calculation completely broken.
In the edma_residue() function we also need to to some correction for the
calculations:
Instead waiting for all EDMA channels to be idle (in a busy system it can
take few iteration to hit a point when all queues are idle) wait for the
event pending on the given channel (SH_ER for hw synchronized channels,
SH_ESR for manually triggered channels).
If the position returned by EMDA is 0 it imiplies that the last paRAM set
has been consumed and we are at the closing dummy set, thus we can conclude
that the transfer is completed and we can return 0 as residue.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
drivers/dma/ti/edma.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
index 3fd7831d1279..48b155cab822 100644
--- a/drivers/dma/ti/edma.c
+++ b/drivers/dma/ti/edma.c
@@ -1039,6 +1039,7 @@ static int edma_config_pset(struct dma_chan *chan, struct edma_pset *epset,
src_cidx = cidx;
dst_bidx = acnt;
dst_cidx = cidx;
+ epset->addr = src_addr;
} else {
dev_err(dev, "%s: direction not implemented yet\n", __func__);
return -EINVAL;
@@ -1749,7 +1750,11 @@ static u32 edma_residue(struct edma_desc *edesc)
int loop_count = EDMA_MAX_TR_WAIT_LOOPS;
struct edma_chan *echan = edesc->echan;
struct edma_pset *pset = edesc->pset;
- dma_addr_t done, pos;
+ dma_addr_t done, pos, pos_old;
+ int channel = EDMA_CHAN_SLOT(echan->ch_num);
+ int idx = EDMA_REG_ARRAY_INDEX(channel);
+ int ch_bit = EDMA_CHANNEL_BIT(channel);
+ int event_reg;
int i;
/*
@@ -1762,16 +1767,20 @@ static u32 edma_residue(struct edma_desc *edesc)
* "pos" may represent a transfer request that is still being
* processed by the EDMACC or EDMATC. We will busy wait until
* any one of the situations occurs:
- * 1. the DMA hardware is idle
- * 2. a new transfer request is setup
+ * 1. while and event is pending for the channel
+ * 2. a position updated
* 3. we hit the loop limit
*/
- while (edma_read(echan->ecc, EDMA_CCSTAT) & EDMA_CCSTAT_ACTV) {
- /* check if a new transfer request is setup */
- if (edma_get_position(echan->ecc,
- echan->slot[0], dst) != pos) {
+ if (is_slave_direction(edesc->direction))
+ event_reg = SH_ER;
+ else
+ event_reg = SH_ESR;
+
+ pos_old = pos;
+ while (edma_shadow0_read_array(echan->ecc, event_reg, idx) & ch_bit) {
+ pos = edma_get_position(echan->ecc, echan->slot[0], dst);
+ if (pos != pos_old)
break;
- }
if (!--loop_count) {
dev_dbg_ratelimited(echan->vchan.chan.device->dev,
@@ -1796,6 +1805,12 @@ static u32 edma_residue(struct edma_desc *edesc)
return edesc->residue_stat;
}
+ /*
+ * If the position is 0, then EDMA loaded the closing dummy slot, the
+ * transfer is completed
+ */
+ if (!pos)
+ return 0;
/*
* For SG operation we catch up with the last processed
* status.
--
Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
next prev parent reply other threads:[~2019-06-18 13:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-18 13:21 [PATCH v4 0/3] dmaengine: ti: edma: Polled completion support Peter Ujfalusi
2019-06-18 13:21 ` [PATCH v4 1/3] dmaengine: ti: edma: Clean up the 2x32bit array register accesses Peter Ujfalusi
2019-06-18 13:21 ` Peter Ujfalusi [this message]
2019-06-18 13:21 ` [PATCH v4 3/3] dmaengine: ti: edma: Support for polled (memcpy) completion Peter Ujfalusi
2019-07-05 6:17 ` Vinod Koul
2019-07-12 21:05 ` Peter Ujfalusi
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