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From: Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>
To: dmaengine@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, Vinod Koul <vkoul@kernel.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Gustavo Pimentel <Gustavo.Pimentel@synopsys.com>
Subject: [PATCH v5 07/15] dmaengine: dw-edma: Improve number of channels check
Date: Thu, 11 Feb 2021 10:12:40 +0100	[thread overview]
Message-ID: <1a42fc97b18012925454013a64b901e06683c77b.1613034728.git.gustavo.pimentel@synopsys.com> (raw)
In-Reply-To: <cover.1613034728.git.gustavo.pimentel@synopsys.com>
In-Reply-To: <cover.1613034728.git.gustavo.pimentel@synopsys.com>

It was added some extra checks to ensure that the driver doesn't try to
use more DMA channels than actually are available in hardware.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
---
 drivers/dma/dw-edma/dw-edma-core.c | 21 +++++++++------------
 drivers/dma/dw-edma/dw-edma-core.h |  2 ++
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 0fe3835..5495cf7 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -914,19 +914,16 @@ int dw_edma_probe(struct dw_edma_chip *chip)
 
 	raw_spin_lock_init(&dw->lock);
 
-	if (!dw->wr_ch_cnt) {
-		/* Find out how many write channels are supported by hardware */
-		dw->wr_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE);
-		if (!dw->wr_ch_cnt)
-			return -EINVAL;
-	}
+	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt,
+			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_WRITE));
+	dw->wr_ch_cnt = min_t(u16, dw->wr_ch_cnt, EDMA_MAX_WR_CH);
 
-	if (!dw->rd_ch_cnt) {
-		/* Find out how many read channels are supported by hardware */
-		dw->rd_ch_cnt = dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ);
-		if (!dw->rd_ch_cnt)
-			return -EINVAL;
-	}
+	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt,
+			      dw_edma_v0_core_ch_count(dw, EDMA_DIR_READ));
+	dw->rd_ch_cnt = min_t(u16, dw->rd_ch_cnt, EDMA_MAX_RD_CH);
+
+	if (!dw->wr_ch_cnt && !dw->rd_ch_cnt)
+		return -EINVAL;
 
 	dev_vdbg(dev, "Channels:\twrite=%d, read=%d\n",
 		 dw->wr_ch_cnt, dw->rd_ch_cnt);
diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h
index f72ebaa..650b1c7 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -15,6 +15,8 @@
 #include "../virt-dma.h"
 
 #define EDMA_LL_SZ					24
+#define EDMA_MAX_WR_CH					8
+#define EDMA_MAX_RD_CH					8
 
 enum dw_edma_dir {
 	EDMA_DIR_WRITE = 0,
-- 
2.7.4


  parent reply	other threads:[~2021-02-11  9:18 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-11  9:12 [PATCH v5 00/15] dmaengine: dw-edma: HDMA support Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 01/15] dmaengine: dw-edma: Add writeq() and readq() for 64 bits architectures Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 02/15] dmaengine: dw-edma: Fix comments offset characters' alignment Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 03/15] dmaengine: dw-edma: Add support for the HDMA feature Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC Gustavo Pimentel
2021-02-11 12:50   ` Krzysztof Wilczyński
2021-02-11 19:42     ` Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 05/15] dmaengine: dw-edma: Add PCIe VSEC data retrieval support Gustavo Pimentel
2021-02-11 12:59   ` Krzysztof Wilczyński
2021-02-11 13:48     ` Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 06/15] dmaengine: dw-edma: Add device_prep_interleave_dma() support Gustavo Pimentel
2021-02-11  9:12 ` Gustavo Pimentel [this message]
2021-02-11  9:12 ` [PATCH v5 08/15] dmaengine: dw-edma: Reorder variables to keep consistency Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 09/15] dmaengine: dw-edma: Improve the linked list and data blocks definition Gustavo Pimentel
2021-02-11 13:08   ` Krzysztof Wilczyński
2021-02-11  9:12 ` [PATCH v5 10/15] dmaengine: dw-edma: Change linked list and data blocks offset and sizes Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 11/15] dmaengine: dw-edma: Move struct dentry variable from static definition into dw_edma struct Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 12/15] dmaengine: dw-edma: Fix crash on loading/unloading driver Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 13/15] dmaengine: dw-edma: Change DMA abreviation from lower into upper case Gustavo Pimentel
2021-02-11  9:12 ` [PATCH v5 14/15] dmaengine: dw-edma: Revert fix scatter-gather address calculation Gustavo Pimentel
2021-02-11 13:09   ` Krzysztof Wilczyński
2021-02-11  9:12 ` [PATCH v5 15/15] dmaengine: dw-edma: Add pcim_iomap_table return check Gustavo Pimentel
2021-02-11 13:14   ` Krzysztof Wilczyński

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