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From: viresh.kumar@st.com (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V2 09/20] dmaengine/amba-pl08x: Simplify pl08x_ensure_on()
Date: Mon, 1 Aug 2011 15:07:19 +0530	[thread overview]
Message-ID: <e55c1235b79772d2f8f33e487fa272b3dd7d3604.1312190881.git.viresh.kumar@st.com> (raw)
In-Reply-To: <cover.1312190881.git.viresh.kumar@st.com>

Simply writing 1 on bit 0 is sufficient instead of reading and clearing bits.
Also as per manual, for bit 3-31 of DMACConfiguration register:
"read undefined, write as 0"

So, we must not rely on values read from this registers bit 3-31.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
 drivers/dma/amba-pl08x.c |    8 +-------
 1 files changed, 1 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 428a67b..da17249 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -1507,13 +1507,7 @@ bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
  */
 static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
 {
-	u32 val;
-
-	val = readl(pl08x->base + PL080_CONFIG);
-	val &= ~(PL080_CONFIG_M2_BE | PL080_CONFIG_M1_BE | PL080_CONFIG_ENABLE);
-	/* We implicitly clear bit 1 and that means little-endian mode */
-	val |= PL080_CONFIG_ENABLE;
-	writel(val, pl08x->base + PL080_CONFIG);
+	writel(PL080_CONFIG_ENABLE, pl08x->base + PL080_CONFIG);
 }
 
 static void pl08x_unmap_buffers(struct pl08x_txd *txd)
-- 
1.7.2.2

  parent reply	other threads:[~2011-08-01  9:37 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-01  9:37 [PATCH V2 00/20] dmaengine/amba-pl08x updates Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 01/20] ARM: asm/pl080.h: Protect against multiple inclusion of header file Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 02/20] dmaengine/amba-pl08x: Resolve formatting issues Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 03/20] dmaengine/amba-pl08x: Rearrange inclusion of header files in ascending order Viresh Kumar
2011-08-01  9:52   ` Sergei Shtylyov
2011-08-01 10:34     ` viresh kumar
2011-08-01  9:37 ` [PATCH V2 04/20] dmaengine/amba-pl08x: pass (*ptr) to sizeof() instead of (struct xyz) Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 05/20] dmaengine/amba-pl08x: Complete doc comment for struct pl08x_txd Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 06/20] dmaengine/amba-pl08x: Remove redundant comment and rewrite original Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 07/20] dmaengine/amba-pl08x: Changing few prints to dev_dbg from dev_info Viresh Kumar
2011-08-04  8:28   ` Koul, Vinod
2011-08-04  9:25     ` viresh kumar
2011-08-04  8:53       ` Koul, Vinod
2011-08-01  9:37 ` [PATCH V2 08/20] dmaengine/amba-pl08x: support runtime PM Viresh Kumar
2011-08-01 10:26   ` Russell King - ARM Linux
2011-08-01 11:55     ` viresh kumar
2011-08-03 12:39   ` Russell King - ARM Linux
2011-08-04  5:19     ` viresh kumar
2011-08-04  5:36       ` Koul, Vinod
2011-08-04  6:31         ` viresh kumar
2011-08-04  7:28           ` Koul, Vinod
2011-08-04  8:42             ` viresh kumar
2011-08-01  9:37 ` Viresh Kumar [this message]
2011-08-01  9:37 ` [PATCH V2 10/20] dmaengine/amba-pl08x: No need to check "ch->signal < 0" Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 11/20] dmaengine/amba-pl08x: Schedule tasklet in case of error interrupt Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 12/20] dmaengine/amba-pl08x: Get rid of pl08x_pre_boundary() Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 13/20] dmaengine/amba-pl08x: max_bytes_per_lli is TRANSFER_SIZE * src_width (not MIN(width)) Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 14/20] dmaengine/amba-pl08x: Add prep_single_byte_llis() routine Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 15/20] dmaengine/amba-pl08x: Align lli_len to max(src.width, dst.width) Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 16/20] dmaengine/amba-pl08x: Choose peripheral bus as master bus Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 17/20] dmaengine/amba-pl08x: Pass flow controller information with slave channel data Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 18/20] dmaengine/amba-pl08x: Add support for sg len greater than one for slave transfers Viresh Kumar
2011-08-04 10:27   ` viresh kumar
2011-08-01  9:37 ` [PATCH V2 19/20] dmaengine/amba-pl08x: Check txd->llis_va before freeing dma_pool Viresh Kumar
2011-08-01  9:37 ` [PATCH V2 20/20] dmaengine/amba-pl08x: Call pl08x_free_txd() instead of calling kfree() directly Viresh Kumar
2011-08-01 11:56 ` [PATCH V3 08/20] dmaengine/amba-pl08x: support runtime PM Viresh Kumar
2011-08-04  8:52   ` Koul, Vinod
2011-08-04  9:41     ` viresh kumar

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