From: viresh.kumar@st.com (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 13/18] dmaengine/amba-pl08x: Align lli_len to max(src.width, dst.width)
Date: Fri, 29 Jul 2011 16:19:23 +0530 [thread overview]
Message-ID: <afe9e5154d96c0f44c64c411c98b5db75969db6c.1311936524.git.viresh.kumar@st.com> (raw)
In-Reply-To: <cover.1311936523.git.viresh.kumar@st.com>
Currently lli_len is aligned to min of two widths, which looks to be incorrect.
Instead it should be aligned to max of both widths.
Lets say, total_size = 441 bytes
MIN: lets check if min() suits or not:
CASE 1: srcwidth = 1, dstwidth = 4
min(src, dst) = 1
i.e. We program transfer size in control reg to 441.
Now, till 440 bytes everything is fine, but on the last byte DMAC can't transfer
1 byte to dst, as its width is 4.
CASE 2: srcwidth = 4, dstwidth = 1
min(src, dst) = 1
i.e. we program transfer size in control reg to 110 (data transferred = 110 * srcwidth).
So, here too 1 byte is left, but on the source side.
MAX: Lets check if max() suits or not:
CASE 3: srcwidth = 1, dstwidth = 4
max(src, dst) = 4
Aligned size is 440
i.e. We program transfer size in control reg to 440.
Now, all 440 bytes will be transferred without any issues.
CASE 4: srcwidth = 4, dstwidth = 1
max(src, dst) = 4
Aligned size is 440
i.e. We program transfer size in control reg to 110 (data transferred = 110 * srcwidth).
Now, also all 440 bytes will be transferred without any issues.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
drivers/dma/amba-pl08x.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 590397d..44f317a 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -662,20 +662,22 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
* width left
*/
while (bd.remainder > (mbus->buswidth - 1)) {
- size_t lli_len, tsize;
+ size_t lli_len, tsize, width;
/*
* If enough left try to send max possible,
* otherwise try to send the remainder
*/
lli_len = min(bd.remainder, max_bytes_per_lli);
+
/*
- * Check against minimum bus alignment: Calculate actual
+ * Check against maximum bus alignment: Calculate actual
* transfer size in relation to bus width and get a
- * maximum remainder of the smallest bus width - 1
+ * maximum remainder of the highest bus width - 1
*/
- tsize = lli_len / min(mbus->buswidth, sbus->buswidth);
- lli_len = tsize * min(mbus->buswidth, sbus->buswidth);
+ width = max(mbus->buswidth, sbus->buswidth);
+ lli_len = (lli_len / width) * width;
+ tsize = lli_len / bd.srcbus.buswidth;
dev_vdbg(&pl08x->adev->dev,
"%s fill lli with single lli chunk of "
--
1.7.2.2
next prev parent reply other threads:[~2011-07-29 10:49 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-29 10:49 [PATCH 00/18] dmaengine/amba-pl08x updates Viresh Kumar
2011-07-29 10:49 ` [PATCH 01/18] ARM: asm/pl080.h: Protect against multiple inclusion of header file Viresh Kumar
2011-07-30 22:16 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 02/18] dmaengine/amba-pl08x: Resolve formatting issues Viresh Kumar
2011-07-29 11:00 ` Russell King - ARM Linux
2011-07-29 11:21 ` viresh kumar
2011-07-29 12:05 ` Koul, Vinod
2011-07-29 15:25 ` viresh kumar
2011-07-29 10:49 ` [PATCH 03/18] dmaengine/amba-pl08x: Complete doc comment for struct pl08x_txd Viresh Kumar
2011-07-29 10:49 ` [PATCH 04/18] dmaengine/amba-pl08x: Remove redundant comment and rewrite original Viresh Kumar
2011-07-29 12:09 ` Koul, Vinod
2011-07-29 15:47 ` viresh kumar
2011-07-29 16:34 ` Russell King - ARM Linux
2011-07-30 22:32 ` Linus Walleij
2011-07-30 22:57 ` Russell King - ARM Linux
2011-07-30 23:37 ` Linus Walleij
2011-07-31 5:51 ` viresh kumar
2011-07-31 9:06 ` Russell King - ARM Linux
2011-07-29 10:49 ` [PATCH 05/18] dmaengine/amba-pl08x: Changing few prints to dev_dbg from dev_info Viresh Kumar
2011-07-30 22:34 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 06/18] dmaengine/amba-pl08x: Simplify pl08x_ensure_on() Viresh Kumar
2011-07-30 22:36 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 07/18] dmaengine/amba-pl08x: Enable/Disable amba_pclk with channel requests Viresh Kumar
2011-07-30 12:07 ` Russell King - ARM Linux
2011-07-30 13:05 ` Russell King - ARM Linux
2011-07-30 23:53 ` Linus Walleij
2011-07-31 0:04 ` Linus Walleij
2011-07-31 17:04 ` Russell King - ARM Linux
2011-08-02 9:05 ` Linus Walleij
2011-08-03 12:55 ` Russell King - ARM Linux
2011-08-09 19:50 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 08/18] dmaengine/amba-pl08x: No need to check "ch->signal < 0" Viresh Kumar
2011-07-31 0:09 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 09/18] dmaengine/amba-pl08x: Schedule tasklet in case of error interrupt Viresh Kumar
2011-07-29 12:16 ` Koul, Vinod
2011-07-29 13:02 ` Russell King - ARM Linux
2011-07-29 15:30 ` viresh kumar
2011-08-04 4:25 ` Koul, Vinod
2011-08-04 5:54 ` viresh kumar
2011-08-04 5:32 ` Koul, Vinod
2011-08-14 8:29 ` Russell King - ARM Linux
2011-07-31 0:19 ` Linus Walleij
2011-07-31 5:33 ` viresh kumar
2011-07-29 10:49 ` [PATCH 10/18] dmaengine/amba-pl08x: Get rid of pl08x_pre_boundary() Viresh Kumar
2011-07-29 11:05 ` Russell King - ARM Linux
2011-07-29 12:32 ` Koul, Vinod
2011-07-29 15:58 ` viresh kumar
2011-07-29 12:19 ` Koul, Vinod
2011-07-29 15:40 ` viresh kumar
2011-07-31 0:24 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 11/18] dmaengine/amba-pl08x: max_bytes_per_lli is TRANSFER_SIZE * src_width (not MIN(width)) Viresh Kumar
2011-07-31 0:27 ` Linus Walleij
2011-07-31 9:09 ` Russell King - ARM Linux
2011-07-29 10:49 ` [PATCH 12/18] dmaengine/amba-pl08x: Add prep_single_byte_llis() routine Viresh Kumar
2011-07-29 11:06 ` Russell King - ARM Linux
2011-07-29 11:30 ` viresh kumar
2011-07-29 10:49 ` Viresh Kumar [this message]
2011-07-29 12:43 ` [PATCH 13/18] dmaengine/amba-pl08x: Align lli_len to max(src.width, dst.width) Koul, Vinod
2011-07-29 15:39 ` viresh kumar
2011-07-31 0:30 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 14/18] dmaengine/amba-pl08x: Choose peripheral bus as master bus Viresh Kumar
2011-07-31 0:36 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 15/18] dmaengine/amba-pl08x: Pass flow controller information with slave channel data Viresh Kumar
2011-07-29 11:10 ` Russell King - ARM Linux
2011-07-29 11:31 ` viresh kumar
2011-07-31 0:40 ` Linus Walleij
2011-07-31 5:36 ` viresh kumar
2011-07-29 10:49 ` [PATCH 16/18] dmaengine/amba-pl08x: Add support for sg len greater than one for slave transfers Viresh Kumar
2011-07-31 0:41 ` Linus Walleij
2011-08-14 8:36 ` Russell King - ARM Linux
2011-08-15 10:11 ` Linus Walleij
2011-08-18 8:38 ` Viresh Kumar
2011-08-21 8:33 ` Russell King - ARM Linux
2011-08-23 4:22 ` Viresh Kumar
2011-08-23 5:20 ` Koul, Vinod
2011-08-26 3:41 ` Viresh Kumar
2011-08-26 8:03 ` Linus Walleij
2011-08-26 8:51 ` Viresh Kumar
2011-09-01 10:07 ` Viresh Kumar
2011-09-07 18:42 ` Koul, Vinod
2011-09-07 23:01 ` Linus Walleij
2011-09-08 3:50 ` Viresh Kumar
2011-09-08 10:29 ` Linus Walleij
2011-09-08 21:54 ` [PATCH 16/18] dmaengine/ambhe rest oa-pl08x: " Vinod Koul
2011-09-20 6:19 ` Vinod Koul
2011-09-20 6:27 ` Viresh Kumar
2011-09-20 8:08 ` Vinod Koul
2011-07-29 10:49 ` [PATCH 17/18] dmaengine/amba-pl08x: Check txd->llis_va before freeing dma_pool Viresh Kumar
2011-07-31 0:44 ` Linus Walleij
2011-07-29 10:49 ` [PATCH 18/18] dmaengine/amba-pl08x: Call pl08x_free_txd() instead of calling kfree() directly Viresh Kumar
2011-07-29 11:15 ` Russell King - ARM Linux
2011-07-29 11:38 ` viresh kumar
2011-07-31 0:45 ` Linus Walleij
2011-07-31 5:39 ` viresh kumar
2011-07-29 10:57 ` [PATCH 00/18] dmaengine/amba-pl08x updates Russell King - ARM Linux
2011-07-29 11:14 ` viresh kumar
2011-07-29 11:19 ` Russell King - ARM Linux
2011-07-29 11:23 ` viresh kumar
2011-07-29 12:43 ` Russell King - ARM Linux
2011-07-29 15:22 ` viresh kumar
2011-07-29 11:58 ` Koul, Vinod
2011-08-01 5:30 ` viresh kumar
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