This patchset is to add memcpy interface for imx-sdma, besides,to
support dmatest and enable config by default, so that could test dma
easily without any other device support such as uart/audio/spi...
Change from v1:
1. remove bus_width check for memcpy since only max bus width needed for
memcpy case to speedup copy.
2. remove DMATEST support patch, since DMATEST is a common memcpy case.
3. split to single patch for SDMA_BD_MAX_CNT instead of '0xffff'
4. move sdma_config_ownership() from alloc_chan into sdma_prep_memcpy.
5. address some minor review comments.
Robin Gong (3):
dmaengine: imx-sdma: add SDMA_BD_MAX_CNT to replace '0xffff'
dmaengine: imx-sdma: add memcpy interface
ARM: configs: imx_v6_v7_defconfig: add DMATEST support
arch/arm/configs/imx_v6_v7_defconfig | 3 +-
drivers/dma/imx-sdma.c | 106 ++++++++++++++++++++++++++++++++---
2 files changed, 99 insertions(+), 10 deletions(-)
--
2.7.4
Add macro SDMA_BD_MAX_CNT to replace '0xffff'.
Signed-off-by: Robin Gong <[email protected]>
---
drivers/dma/imx-sdma.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 3b622d6..e3d5e73 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -185,6 +185,7 @@
* Mode/Count of data node descriptors - IPCv2
*/
struct sdma_mode_count {
+#define SDMA_BD_MAX_CNT 0xffff
u32 count : 16; /* size of the buffer pointed by this BD */
u32 status : 8; /* E,R,I,C,W,D status bits stored here */
u32 command : 8; /* command mostly used for channel 0 */
@@ -1344,9 +1345,9 @@ static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
count = sg_dma_len(sg);
- if (count > 0xffff) {
+ if (count > SDMA_BD_MAX_CNT) {
dev_err(sdma->dev, "SDMA channel %d: maximum bytes for sg entry exceeded: %d > %d\n",
- channel, count, 0xffff);
+ channel, count, SDMA_BD_MAX_CNT);
goto err_bd_out;
}
@@ -1421,9 +1422,9 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic(
sdmac->flags |= IMX_DMA_SG_LOOP;
- if (period_len > 0xffff) {
+ if (period_len > SDMA_BD_MAX_CNT) {
dev_err(sdma->dev, "SDMA channel %d: maximum period size exceeded: %zu > %d\n",
- channel, period_len, 0xffff);
+ channel, period_len, SDMA_BD_MAX_CNT);
goto err_bd_out;
}
@@ -1970,7 +1971,7 @@ static int sdma_probe(struct platform_device *pdev)
sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
sdma->dma_device.device_issue_pending = sdma_issue_pending;
sdma->dma_device.dev->dma_parms = &sdma->dma_parms;
- dma_set_max_seg_size(sdma->dma_device.dev, 65535);
+ dma_set_max_seg_size(sdma->dma_device.dev, SDMA_BD_MAX_CNT);
platform_set_drvdata(pdev, sdma);
--
2.7.4
Add MEMCPY capability for imx-sdma driver.
Signed-off-by: Robin Gong <[email protected]>
---
drivers/dma/imx-sdma.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 92 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index e3d5e73..ef50f2c 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -342,6 +342,7 @@ struct sdma_desc {
* @pc_from_device: script address for those device_2_memory
* @pc_to_device: script address for those memory_2_device
* @device_to_device: script address for those device_2_device
+ * @pc_to_pc: script address for those memory_2_memory
* @flags: loop mode or not
* @per_address: peripheral source or destination address in common case
* destination address in p_2_p case
@@ -367,6 +368,7 @@ struct sdma_channel {
enum dma_slave_buswidth word_size;
unsigned int pc_from_device, pc_to_device;
unsigned int device_to_device;
+ unsigned int pc_to_pc;
unsigned long flags;
dma_addr_t per_address, per_address2;
unsigned long event_mask[2];
@@ -869,14 +871,16 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
* These are needed once we start to support transfers between
* two peripherals or memory-to-memory transfers
*/
- int per_2_per = 0;
+ int per_2_per = 0, emi_2_emi = 0;
sdmac->pc_from_device = 0;
sdmac->pc_to_device = 0;
sdmac->device_to_device = 0;
+ sdmac->pc_to_pc = 0;
switch (peripheral_type) {
case IMX_DMATYPE_MEMORY:
+ emi_2_emi = sdma->script_addrs->ap_2_ap_addr;
break;
case IMX_DMATYPE_DSP:
emi_2_per = sdma->script_addrs->bp_2_ap_addr;
@@ -949,6 +953,7 @@ static void sdma_get_pc(struct sdma_channel *sdmac,
sdmac->pc_from_device = per_2_emi;
sdmac->pc_to_device = emi_2_per;
sdmac->device_to_device = per_2_per;
+ sdmac->pc_to_pc = emi_2_emi;
}
static int sdma_load_context(struct sdma_channel *sdmac)
@@ -965,6 +970,8 @@ static int sdma_load_context(struct sdma_channel *sdmac)
load_address = sdmac->pc_from_device;
else if (sdmac->direction == DMA_DEV_TO_DEV)
load_address = sdmac->device_to_device;
+ else if (sdmac->direction == DMA_MEM_TO_MEM)
+ load_address = sdmac->pc_to_pc;
else
load_address = sdmac->pc_to_device;
@@ -1214,10 +1221,28 @@ static int sdma_alloc_chan_resources(struct dma_chan *chan)
{
struct sdma_channel *sdmac = to_sdma_chan(chan);
struct imx_dma_data *data = chan->private;
+ struct imx_dma_data mem_data;
int prio, ret;
- if (!data)
- return -EINVAL;
+ /*
+ * MEMCPY may never setup chan->private by filter function such as
+ * dmatest, thus create 'struct imx_dma_data mem_data' for this case.
+ * Please note in any other slave case, you have to setup chan->private
+ * with 'struct imx_dma_data' in your own filter function if you want to
+ * request dma channel by dma_request_channel() rather than
+ * dma_request_slave_channel(). Othwise, 'MEMCPY in case?' will appear
+ * to warn you to correct your filter function.
+ */
+ if (!data) {
+ dev_dbg(sdmac->sdma->dev, "MEMCPY in case?\n");
+ mem_data.priority = 2;
+ mem_data.peripheral_type = IMX_DMATYPE_MEMORY;
+ mem_data.dma_request = 0;
+ mem_data.dma_request2 = 0;
+ data = &mem_data;
+
+ sdma_get_pc(sdmac, IMX_DMATYPE_MEMORY);
+ }
switch (data->priority) {
case DMA_PRIO_HIGH:
@@ -1307,6 +1332,10 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
if (sdma_alloc_bd(desc))
goto err_desc_out;
+ /* No slave_config called in MEMCPY case, so do here */
+ if (direction == DMA_MEM_TO_MEM)
+ sdma_config_ownership(sdmac, false, true, false);
+
if (sdma_load_context(sdmac))
goto err_desc_out;
@@ -1318,6 +1347,63 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
return NULL;
}
+static struct dma_async_tx_descriptor *sdma_prep_memcpy(
+ struct dma_chan *chan, dma_addr_t dma_dst,
+ dma_addr_t dma_src, size_t len, unsigned long flags)
+{
+ struct sdma_channel *sdmac = to_sdma_chan(chan);
+ struct sdma_engine *sdma = sdmac->sdma;
+ int channel = sdmac->channel;
+ size_t count;
+ int i = 0, param;
+ struct sdma_buffer_descriptor *bd;
+ struct sdma_desc *desc;
+
+ if (!chan || !len)
+ return NULL;
+
+ dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
+ &dma_src, &dma_dst, len, channel);
+
+ desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
+ len / SDMA_BD_MAX_CNT + 1);
+ if (!desc)
+ return NULL;
+
+ do {
+ count = min_t(size_t, len, SDMA_BD_MAX_CNT);
+ bd = &desc->bd[i];
+ bd->buffer_addr = dma_src;
+ bd->ext_buffer_addr = dma_dst;
+ bd->mode.count = count;
+ desc->chn_count += count;
+ /* align with sdma->dma_device.copy_align: 4bytes */
+ bd->mode.command = 0;
+
+ dma_src += count;
+ dma_dst += count;
+ len -= count;
+ i++;
+
+ param = BD_DONE | BD_EXTD | BD_CONT;
+ /* last bd */
+ if (!len) {
+ param |= BD_INTR;
+ param |= BD_LAST;
+ param &= ~BD_CONT;
+ }
+
+ dev_dbg(sdma->dev, "entry %d: count: %zd dma: 0x%x %s%s\n",
+ i, count, bd->buffer_addr,
+ param & BD_WRAP ? "wrap" : "",
+ param & BD_INTR ? " intr" : "");
+
+ bd->mode.status = param;
+ } while (len);
+
+ return vchan_tx_prep(&sdmac->vc, &desc->vd, flags);
+}
+
static struct dma_async_tx_descriptor *sdma_prep_slave_sg(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
@@ -1903,6 +1989,7 @@ static int sdma_probe(struct platform_device *pdev)
dma_cap_set(DMA_SLAVE, sdma->dma_device.cap_mask);
dma_cap_set(DMA_CYCLIC, sdma->dma_device.cap_mask);
+ dma_cap_set(DMA_MEMCPY, sdma->dma_device.cap_mask);
INIT_LIST_HEAD(&sdma->dma_device.channels);
/* Initialize channel parameters */
@@ -1969,8 +2056,10 @@ static int sdma_probe(struct platform_device *pdev)
sdma->dma_device.dst_addr_widths = SDMA_DMA_BUSWIDTHS;
sdma->dma_device.directions = SDMA_DMA_DIRECTIONS;
sdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+ sdma->dma_device.device_prep_dma_memcpy = sdma_prep_memcpy;
sdma->dma_device.device_issue_pending = sdma_issue_pending;
sdma->dma_device.dev->dma_parms = &sdma->dma_parms;
+ sdma->dma_device.copy_align = DMAENGINE_ALIGN_4_BYTES;
dma_set_max_seg_size(sdma->dma_device.dev, SDMA_BD_MAX_CNT);
platform_set_drvdata(pdev, sdma);
--
2.7.4
Add DMATEST support and remove invalid options, such as
CONFIG_BT_HCIUART_H4 is default enabled and CONFIG_SND_SOC_IMX_WM8962
is out of date and not appear in any config file. Please refer to
Documentation/driver-api/dmaengine/dmatest.rst to test MEMCPY feature
of imx-sdma.
Signed-off-by: Robin Gong <[email protected]>
---
arch/arm/configs/imx_v6_v7_defconfig | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/arm/configs/imx_v6_v7_defconfig b/arch/arm/configs/imx_v6_v7_defconfig
index e381d05..f28d4d9 100644
--- a/arch/arm/configs/imx_v6_v7_defconfig
+++ b/arch/arm/configs/imx_v6_v7_defconfig
@@ -81,7 +81,6 @@ CONFIG_CAN=y
CONFIG_CAN_FLEXCAN=y
CONFIG_BT=y
CONFIG_BT_HCIUART=y
-CONFIG_BT_HCIUART_H4=y
CONFIG_BT_HCIUART_LL=y
CONFIG_CFG80211=y
CONFIG_CFG80211_WEXT=y
@@ -282,7 +281,6 @@ CONFIG_SND_SOC_FSL_ASRC=y
CONFIG_SND_IMX_SOC=y
CONFIG_SND_SOC_PHYCORE_AC97=y
CONFIG_SND_SOC_EUKREA_TLV320=y
-CONFIG_SND_SOC_IMX_WM8962=y
CONFIG_SND_SOC_IMX_ES8328=y
CONFIG_SND_SOC_IMX_SGTL5000=y
CONFIG_SND_SOC_IMX_SPDIF=y
@@ -371,6 +369,7 @@ CONFIG_DMADEVICES=y
CONFIG_FSL_EDMA=y
CONFIG_IMX_SDMA=y
CONFIG_MXS_DMA=y
+CONFIG_DMATEST=m
CONFIG_STAGING=y
CONFIG_STAGING_MEDIA=y
CONFIG_VIDEO_IMX_MEDIA=y
--
2.7.4
On Fri, Jul 13, 2018 at 09:08:46PM +0800, Robin Gong wrote:
> Add MEMCPY capability for imx-sdma driver.
>
> Signed-off-by: Robin Gong <[email protected]>
> ---
> drivers/dma/imx-sdma.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 92 insertions(+), 3 deletions(-)
>
> @@ -1318,6 +1347,63 @@ static struct sdma_desc *sdma_transfer_init(struct sdma_channel *sdmac,
> return NULL;
> }
>
> +static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> + struct dma_chan *chan, dma_addr_t dma_dst,
> + dma_addr_t dma_src, size_t len, unsigned long flags)
> +{
> + struct sdma_channel *sdmac = to_sdma_chan(chan);
> + struct sdma_engine *sdma = sdmac->sdma;
> + int channel = sdmac->channel;
> + size_t count;
> + int i = 0, param;
> + struct sdma_buffer_descriptor *bd;
> + struct sdma_desc *desc;
> +
> + if (!chan || !len)
> + return NULL;
> +
> + dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
> + &dma_src, &dma_dst, len, channel);
> +
> + desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
> + len / SDMA_BD_MAX_CNT + 1);
> + if (!desc)
> + return NULL;
> +
> + do {
> + count = min_t(size_t, len, SDMA_BD_MAX_CNT);
> + bd = &desc->bd[i];
> + bd->buffer_addr = dma_src;
> + bd->ext_buffer_addr = dma_dst;
> + bd->mode.count = count;
> + desc->chn_count += count;
> + /* align with sdma->dma_device.copy_align: 4bytes */
> + bd->mode.command = 0;
> +
> + dma_src += count;
> + dma_dst += count;
> + len -= count;
> + i++;
NACK.
Please actually look at your code and find out where you do unaligned DMA
accesses. Hint: What happens when this loop body is executed more than once?
Sascha
> +
> + param = BD_DONE | BD_EXTD | BD_CONT;
> + /* last bd */
> + if (!len) {
> + param |= BD_INTR;
> + param |= BD_LAST;
> + param &= ~BD_CONT;
> + }
> +
> + dev_dbg(sdma->dev, "entry %d: count: %zd dma: 0x%x %s%s\n",
> + i, count, bd->buffer_addr,
> + param & BD_WRAP ? "wrap" : "",
> + param & BD_INTR ? " intr" : "");
> +
> + bd->mode.status = param;
> + } while (len);
> +
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
On Fri, Jul 13, 2018 at 09:08:47PM +0800, Robin Gong wrote:
> Add DMATEST support and remove invalid options, such as
> CONFIG_BT_HCIUART_H4 is default enabled and CONFIG_SND_SOC_IMX_WM8962
> is out of date and not appear in any config file. Please refer to
> Documentation/driver-api/dmaengine/dmatest.rst to test MEMCPY feature
> of imx-sdma.
>
> Signed-off-by: Robin Gong <[email protected]>
Applied this one, thanks.
> -----Original Message-----
> From: Sascha Hauer [mailto:[email protected]]
> Sent: 2018??7??13?? 14:16
> To: Robin Gong <[email protected]>
> Cc: [email protected]; [email protected]; [email protected]; Fabio
> Estevam <[email protected]>; [email protected];
> [email protected]; [email protected];
> [email protected]; [email protected]; dl-linux-imx
> <[email protected]>
> Subject: Re: [PATCH v2 2/3] dmaengine: imx-sdma: add memcpy interface
>
> On Fri, Jul 13, 2018 at 09:08:46PM +0800, Robin Gong wrote:
> > Add MEMCPY capability for imx-sdma driver.
> >
> > Signed-off-by: Robin Gong <[email protected]>
> > ---
> > drivers/dma/imx-sdma.c | 95
> > ++++++++++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 92 insertions(+), 3 deletions(-)
> >
> > @@ -1318,6 +1347,63 @@ static struct sdma_desc
> *sdma_transfer_init(struct sdma_channel *sdmac,
> > return NULL;
> > }
> >
> > +static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> > + struct dma_chan *chan, dma_addr_t dma_dst,
> > + dma_addr_t dma_src, size_t len, unsigned long flags) {
> > + struct sdma_channel *sdmac = to_sdma_chan(chan);
> > + struct sdma_engine *sdma = sdmac->sdma;
> > + int channel = sdmac->channel;
> > + size_t count;
> > + int i = 0, param;
> > + struct sdma_buffer_descriptor *bd;
> > + struct sdma_desc *desc;
> > +
> > + if (!chan || !len)
> > + return NULL;
> > +
> > + dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
> > + &dma_src, &dma_dst, len, channel);
> > +
> > + desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
> > + len / SDMA_BD_MAX_CNT + 1);
> > + if (!desc)
> > + return NULL;
> > +
> > + do {
> > + count = min_t(size_t, len, SDMA_BD_MAX_CNT);
> > + bd = &desc->bd[i];
> > + bd->buffer_addr = dma_src;
> > + bd->ext_buffer_addr = dma_dst;
> > + bd->mode.count = count;
> > + desc->chn_count += count;
> > + /* align with sdma->dma_device.copy_align: 4bytes */
> > + bd->mode.command = 0;
> > +
> > + dma_src += count;
> > + dma_dst += count;
> > + len -= count;
> > + i++;
>
> NACK.
>
> Please actually look at your code and find out where you do unaligned DMA
> accesses. Hint: What happens when this loop body is executed more than
> once?
>
> Sascha
Actually internal sdma script has already take such 'align' matter like below:
Burst with words if source/dest address and data length are all aligned with words, burst with
Byte if not. So I will remove the comment '/* align with sdma->dma_device.copy_align: 4bytes */'
In v3. Besides, I have found another bug which introduced by my virt-dma patch. Will send
V3 later.
>
> > +
> > + param = BD_DONE | BD_EXTD | BD_CONT;
> > + /* last bd */
> > + if (!len) {
> > + param |= BD_INTR;
> > + param |= BD_LAST;
> > + param &= ~BD_CONT;
> > + }
> > +
> > + dev_dbg(sdma->dev, "entry %d: count: %zd dma: 0x%x %s%s\n",
> > + i, count, bd->buffer_addr,
> > + param & BD_WRAP ? "wrap" : "",
> > + param & BD_INTR ? " intr" : "");
> > +
> > + bd->mode.status = param;
> > + } while (len);
> > +
>
> --
> Pengutronix e.K. |
> |
> Industrial Linux Solutions |
> https://emea01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.
> pengutronix.de%2F&data=02%7C01%7Cyibin.gong%40nxp.com%7Cf78f9
> 91028e64b45cf7508d5e888310d%7C686ea1d3bc2b4c6fa92cd99c5c301635%7
> C0%7C0%7C636670594003030732&sdata=zyDkLHVl4VneD05f4VvaY82m
> ZITkybewrXyCj2YRu%2FI%3D&reserved=0 |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> Amtsgericht Hildesheim, HRA 2686 | Fax:
> +49-5121-206917-5555 |
On Fri, Jul 20, 2018 at 09:40:51AM +0000, Robin Gong wrote:
> > -----Original Message-----
> > From: Sascha Hauer [mailto:[email protected]]
> > Sent: 2018年7月13日 14:16
> > To: Robin Gong <[email protected]>
> > Cc: [email protected]; [email protected]; [email protected]; Fabio
> > Estevam <[email protected]>; [email protected];
> > [email protected]; [email protected];
> > [email protected]; [email protected]; dl-linux-imx
> > <[email protected]>
> > Subject: Re: [PATCH v2 2/3] dmaengine: imx-sdma: add memcpy interface
> >
> > On Fri, Jul 13, 2018 at 09:08:46PM +0800, Robin Gong wrote:
> > > Add MEMCPY capability for imx-sdma driver.
> > >
> > > Signed-off-by: Robin Gong <[email protected]>
> > > ---
> > > drivers/dma/imx-sdma.c | 95
> > > ++++++++++++++++++++++++++++++++++++++++++++++++--
> > > 1 file changed, 92 insertions(+), 3 deletions(-)
> > >
> > > @@ -1318,6 +1347,63 @@ static struct sdma_desc
> > *sdma_transfer_init(struct sdma_channel *sdmac,
> > > return NULL;
> > > }
> > >
> > > +static struct dma_async_tx_descriptor *sdma_prep_memcpy(
> > > + struct dma_chan *chan, dma_addr_t dma_dst,
> > > + dma_addr_t dma_src, size_t len, unsigned long flags) {
> > > + struct sdma_channel *sdmac = to_sdma_chan(chan);
> > > + struct sdma_engine *sdma = sdmac->sdma;
> > > + int channel = sdmac->channel;
> > > + size_t count;
> > > + int i = 0, param;
> > > + struct sdma_buffer_descriptor *bd;
> > > + struct sdma_desc *desc;
> > > +
> > > + if (!chan || !len)
> > > + return NULL;
> > > +
> > > + dev_dbg(sdma->dev, "memcpy: %pad->%pad, len=%zu, channel=%d.\n",
> > > + &dma_src, &dma_dst, len, channel);
> > > +
> > > + desc = sdma_transfer_init(sdmac, DMA_MEM_TO_MEM,
> > > + len / SDMA_BD_MAX_CNT + 1);
> > > + if (!desc)
> > > + return NULL;
> > > +
> > > + do {
> > > + count = min_t(size_t, len, SDMA_BD_MAX_CNT);
> > > + bd = &desc->bd[i];
> > > + bd->buffer_addr = dma_src;
> > > + bd->ext_buffer_addr = dma_dst;
> > > + bd->mode.count = count;
> > > + desc->chn_count += count;
> > > + /* align with sdma->dma_device.copy_align: 4bytes */
> > > + bd->mode.command = 0;
> > > +
> > > + dma_src += count;
> > > + dma_dst += count;
> > > + len -= count;
> > > + i++;
> >
> > NACK.
> >
> > Please actually look at your code and find out where you do unaligned DMA
> > accesses. Hint: What happens when this loop body is executed more than
> > once?
> >
> > Sascha
> Actually internal sdma script has already take such 'align' matter like below:
> Burst with words if source/dest address and data length are all aligned with words, burst with
> Byte if not.
If that's the case why did you add the DMAENGINE_ALIGN_4_BYTES flag in the
first place?
Also, if the SDMA script falls back to byte copy when necessary, doing
so probably has performance impacts, so I wonder why you don't just cut
'count' to something that is four byte aligned.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |