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From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	Vinod Koul <vkoul@kernel.org>, Rob Herring <robh@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Cai Huoqing <cai.huoqing@linux.dev>,
	Robin Murphy <robin.murphy@arm.com>,
	Jingoo Han <jingoohan1@gmail.com>, Frank Li <Frank.Li@nxp.com>,
	Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: "Serge Semin" <Sergey.Semin@baikalelectronics.ru>,
	"Serge Semin" <fancer.lancer@gmail.com>,
	"Alexey Malahov" <Alexey.Malahov@baikalelectronics.ru>,
	"Pavel Parkhomenko" <Pavel.Parkhomenko@baikalelectronics.ru>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	caihuoqing <caihuoqing@baidu.com>,
	linux-pci@vger.kernel.org, dmaengine@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Gustavo Pimentel" <Gustavo.Pimentel@synopsys.com>
Subject: [PATCH v6 06/24] dmaengine: dw-edma: Fix invalid interleaved xfers semantics
Date: Tue, 8 Nov 2022 00:04:20 +0300	[thread overview]
Message-ID: <20221107210438.1515-7-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20221107210438.1515-1-Sergey.Semin@baikalelectronics.ru>

The interleaved DMA transfer support added in commit 85e7518f42c8
("dmaengine: dw-edma: Add device_prep_interleave_dma() support") seems
contradicting to what the DMA-engine defines. The next conditional
statements:
	if (!xfer->xfer.il->numf)
		return NULL;
	if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
		return NULL;
basically mean that numf can't be zero and frame_size must always be zero,
otherwise the transfer won't be executed. But further the transfer
execution method takes the frames size from the
dma_interleaved_template.sgl[] array for each frame. That array in
accordance with [1] is supposed to be of
dma_interleaved_template.frame_size size, which as we discovered before
the code expects to be zero. So judging by the dw_edma_device_transfer()
implementation the method implies the dma_interleaved_template.sgl[] array
being of dma_interleaved_template.numf size, which is wrong. Since the
dw_edma_device_transfer() method doesn't permit
dma_interleaved_template.frame_size being non-zero then actual multi-chunk
interleaved transfer turns to be unsupported even though the code implies
having it supported.

Let's fix that by adding a fully functioning support of the interleaved
DMA transfers. First of all dma_interleaved_template.frame_size is
supposed to be greater or equal to one thus having at least simple linear
chunked frames. Secondly we can create a walk-through all over the chunks
and frames just by initializing the number of the eDMA burst transactios
as a multiple of dma_interleaved_template.numf and
dma_interleaved_template.frame_size and getting the frame_size-modulo of
the iteration step as an index of the dma_interleaved_template.sgl[]
array. The rest of the dw_edma_device_transfer() method code can be left
unchanged.

[1] include/linux/dmaengine.h: doc struct dma_interleaved_template

Fixes: 85e7518f42c8 ("dmaengine: dw-edma: Add device_prep_interleave_dma() support")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/dw-edma/dw-edma-core.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 35588e14f79a..d5c4192141ef 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -332,6 +332,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 	struct dw_edma_chunk *chunk;
 	struct dw_edma_burst *burst;
 	struct dw_edma_desc *desc;
+	size_t fsz = 0;
 	u32 cnt = 0;
 	int i;
 
@@ -381,9 +382,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		if (xfer->xfer.sg.len < 1)
 			return NULL;
 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
-		if (!xfer->xfer.il->numf)
-			return NULL;
-		if (xfer->xfer.il->numf > 0 && xfer->xfer.il->frame_size > 0)
+		if (!xfer->xfer.il->numf || xfer->xfer.il->frame_size < 1)
 			return NULL;
 		if (!xfer->xfer.il->src_inc || !xfer->xfer.il->dst_inc)
 			return NULL;
@@ -413,10 +412,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		cnt = xfer->xfer.sg.len;
 		sg = xfer->xfer.sg.sgl;
 	} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
-		if (xfer->xfer.il->numf > 0)
-			cnt = xfer->xfer.il->numf;
-		else
-			cnt = xfer->xfer.il->frame_size;
+		cnt = xfer->xfer.il->numf * xfer->xfer.il->frame_size;
+		fsz = xfer->xfer.il->frame_size;
 	}
 
 	for (i = 0; i < cnt; i++) {
@@ -438,7 +435,7 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		else if (xfer->type == EDMA_XFER_SCATTER_GATHER)
 			burst->sz = sg_dma_len(sg);
 		else if (xfer->type == EDMA_XFER_INTERLEAVED)
-			burst->sz = xfer->xfer.il->sgl[i].size;
+			burst->sz = xfer->xfer.il->sgl[i % fsz].size;
 
 		chunk->ll_region.sz += burst->sz;
 		desc->alloc_sz += burst->sz;
@@ -481,10 +478,9 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 
 		if (xfer->type == EDMA_XFER_SCATTER_GATHER) {
 			sg = sg_next(sg);
-		} else if (xfer->type == EDMA_XFER_INTERLEAVED &&
-			   xfer->xfer.il->frame_size > 0) {
+		} else if (xfer->type == EDMA_XFER_INTERLEAVED) {
 			struct dma_interleaved_template *il = xfer->xfer.il;
-			struct data_chunk *dc = &il->sgl[i];
+			struct data_chunk *dc = &il->sgl[i % fsz];
 
 			src_addr += burst->sz;
 			if (il->src_sgl)
-- 
2.38.0



  parent reply	other threads:[~2022-11-07 21:04 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-07 21:04 [PATCH v6 00/24] dmaengine: dw-edma: Add RP/EP local DMA controllers support Serge Semin
2022-11-07 21:04 ` [PATCH v6 01/24] dmaengine: Fix dma_slave_config.dst_addr description Serge Semin
2022-11-07 21:04 ` [PATCH v6 02/24] dmaengine: dw-edma: Release requested IRQs on failure Serge Semin
2022-11-07 21:04 ` [PATCH v6 03/24] dmaengine: dw-edma: Convert ll/dt phys-address to PCIe bus/DMA address Serge Semin
2022-11-07 21:04 ` [PATCH v6 04/24] dmaengine: dw-edma: Fix missing src/dst address of the interleaved xfers Serge Semin
2022-11-07 21:04 ` [PATCH v6 05/24] dmaengine: dw-edma: Don't permit non-inc " Serge Semin
2022-11-07 21:04 ` Serge Semin [this message]
2022-11-07 21:04 ` [PATCH v6 07/24] dmaengine: dw-edma: Add CPU to PCIe bus address translation Serge Semin
2022-11-07 21:04 ` [PATCH v6 08/24] dmaengine: dw-edma: Add PCIe bus address getter to the remote EP glue-driver Serge Semin
2022-11-07 21:04 ` [PATCH v6 09/24] dmaengine: dw-edma: Drop chancnt initialization Serge Semin
2022-11-07 21:04 ` [PATCH v6 10/24] dmaengine: dw-edma: Fix DebugFS reg entry type Serge Semin
2022-11-07 21:04 ` [PATCH v6 11/24] dmaengine: dw-edma: Stop checking debugfs_create_*() return value Serge Semin
2022-11-07 21:04 ` [PATCH v6 12/24] dmaengine: dw-edma: Add dw_edma prefix to the DebugFS nodes descriptor Serge Semin
2022-11-07 21:04 ` [PATCH v6 13/24] dmaengine: dw-edma: Convert DebugFS descs to being kz-allocated Serge Semin
2022-11-07 21:04 ` [PATCH v6 14/24] dmaengine: dw-edma: Rename DebugFS dentry variables to 'dent' Serge Semin
2022-11-07 21:04 ` [PATCH v6 15/24] dmaengine: dw-edma: Simplify the DebugFS context CSRs init procedure Serge Semin
2022-11-07 21:04 ` [PATCH v6 16/24] dmaengine: dw-edma: Move eDMA data pointer to DebugFS node descriptor Serge Semin
2022-11-07 21:04 ` [PATCH v6 17/24] dmaengine: dw-edma: Join Write/Read channels into a single device Serge Semin
2022-11-07 21:04 ` [PATCH v6 18/24] dmaengine: dw-edma: Use DMA-engine device DebugFS subdirectory Serge Semin
2022-11-07 21:04 ` [PATCH v6 19/24] dmaengine: dw-edma: Use non-atomic io-64 methods Serge Semin
2022-11-07 21:04 ` [PATCH v6 20/24] dmaengine: dw-edma: Drop DT-region allocation Serge Semin
2022-11-07 21:04 ` [PATCH v6 21/24] dmaengine: dw-edma: Replace chip ID number with device name Serge Semin
2022-11-07 21:04 ` [PATCH v6 22/24] dmaengine: dw-edma: Bypass dma-ranges mapping for the local setup Serge Semin
2022-11-07 21:11   ` Serge Semin
2022-11-25 15:32     ` Robin Murphy
2022-11-26 23:45       ` Serge Semin
2022-11-30  0:15         ` Serge Semin
2022-12-01 11:52         ` Robin Murphy
2022-12-11 17:33           ` Serge Semin
2022-11-07 21:04 ` [PATCH v6 23/24] dmaengine: dw-edma: Skip cleanup procedure if no private data found Serge Semin
2022-11-07 21:04 ` [PATCH v6 24/24] PCI: dwc: Add DW eDMA engine support Serge Semin

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