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From: Ben Walker <benjamin.walker@intel.com>
To: vkoul@kernel.org
Cc: dmaengine@vger.kernel.org, ludovic.desroches@microchip.com,
	okaya@kernel.org, dave.jiang@intel.com,
	Ben Walker <benjamin.walker@intel.com>,
	Tudor Ambarus <tudor.ambarus@microchip.com>
Subject: [RFC PATCH 3/4] dmaengine: at_xdmac: In at_xdmac_prep_dma_memset, treat value as a single byte
Date: Fri, 28 Jan 2022 11:39:47 -0700	[thread overview]
Message-ID: <20220128183948.3924558-4-benjamin.walker@intel.com> (raw)
In-Reply-To: <20220128183948.3924558-1-benjamin.walker@intel.com>

The value passed in to .prep_dma_memset is to be treated as a single
byte repeating pattern.

Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 drivers/dma/at_xdmac.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index a1da2b4b6d732..547778fc6445b 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1202,6 +1202,7 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
 	unsigned long		flags;
 	size_t			ublen;
 	u32			dwidth;
+	unsigned char		pattern;
 	/*
 	 * WARNING: The channel configuration is set here since there is no
 	 * dmaengine_slave_config call in this case. Moreover we don't know the
@@ -1244,10 +1245,16 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
 
 	chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
 
+	/* Only the first byte of value is to be used according to dmaengine */
+	pattern = (unsigned char)value;
+
 	ublen = len >> dwidth;
 
 	desc->lld.mbr_da = dst_addr;
-	desc->lld.mbr_ds = value;
+	desc->lld.mbr_ds = (pattern << 24) |
+			   (pattern << 16) |
+			   (pattern << 8) |
+			   pattern;
 	desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
 		| AT_XDMAC_MBR_UBC_NDEN
 		| AT_XDMAC_MBR_UBC_NSEN
-- 
2.33.1


  parent reply	other threads:[~2022-01-28 18:41 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-28 18:39 [RFC PATCH 0/4] dmaengine: memset clarifications and fixes Ben Walker
2022-01-28 18:39 ` [RFC PATCH 1/4] dmaengine: Document dmaengine_prep_dma_memset Ben Walker
2022-02-15 11:44   ` Vinod Koul
2022-02-18 21:37     ` Walker, Benjamin
2022-01-28 18:39 ` [RFC PATCH 2/4] dmaengine: at_hdmac: In atc_prep_dma_memset, treat value as a single byte Ben Walker
2022-02-15 11:47   ` Vinod Koul
2022-02-18 21:42     ` Walker, Benjamin
2022-01-28 18:39 ` Ben Walker [this message]
2022-01-28 18:39 ` [RFC PATCH 4/4] dmaengine: hidma: In hidma_prep_dma_memset " Ben Walker

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