The purpose of the DMAFLUSHP instruction:
- Tell the peripheral to clear its status and control registers.
- Send a message to the peripheral to resend its level status.
There are 3 timings described in PL330 Technical Reference Manual:
- Timing 1: Burst request, can work well without DMAFLUSHP.
- Timing 2: Single and burst request, DMAC will ignore the single
transfer request. This timing happens if there are single
and burst request.
- Timing 3: Single transfers for a burst request, DMAC should signals
datype to request the peripheral to flush the contents of
any control registers. This timing happens if there is
not enough MFIFO to places the burst data.
A peripheral may signal a DMA request during the execution of
DMAFLUSHP instruction, that cause DMA request being ignored by DMAC.
But DMAC and all peripherals on RK3X SoCs DO NOT support DMAFLUSHP.
It can't send a message to the peripheral to resend DMA request,
and the peripheral can't acknowledge a flush request from DMAC.
So all DMA requests should NOT be ignored by DMAC, and DMAC will not
notify the peripheral to flush.
To fix this problem, we need:
- Do NOT execute DMAFLUSHP instruction.
- Timing 2 and timing 3 should not happen.
Because on RK3X SoCs, there are 6 or below channels and 32 MFIFO depth
for DMAC_BUS, and 8 channels and 64 MFIFO depth for DMAC_PERI, it is
impossible to hit the timing 3 if burst length is equal or less than 4.
Since the request type signal by the peripheral can only be set by
software. We can set Rockchip Soc's GRF_PERIDMAC_CON0[2:1] to select single
or burst request, if it is set b01, all of the peripharals will signal a brust
request. So the timing 2 will not happen, too.
So DMAC on RK3X can support single or burst transfer, but can't support
mixed transfer.
Because burst transfer is more efficient than single transfer, this is
confirmed by our ASIC team, who strongly suggest to use burst transfer.
And this is confirmed by Addy's test on RK3288-Pink2 board, the speed of
spi flash burst transfer will increase about two times than single transfer.
Also, I have tested dw_mmc with pl330 on RK3188 platform to double confirm
the result. That means burst transfer is reansonable.
So we need a quirk not to execute DMAFLUSHP instruction and to use burst
transfer.
Note:
- The Rockchip Soc default value of GRF_PERIDMAC_CON0[2:1] is b01. To
support brust transfer, these bits should not be changed in bootloader.
Changes in v2:
- amend the author
- reorder the patches suggested by Doug
- add Reviewed-by: Doug Anderson <[email protected]> for
rk3288.dtsi patch and arm-pl330.txt patch
- amend Olof's mail address
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
- add From original author.
- remove Sunny's tag
Addy Ke (2):
DMA: pl330: add quirk for broken no flushp
ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3288 platform
Boojin Kim (1):
DMA: pl330: support burst mode for dev-to-mem and mem-to-dev transmit
Shawn Lin (2):
Documentation: arm-pl330: add description of
arm,pl330-broken-no-flushp
ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3xxx platform
.../devicetree/bindings/dma/arm-pl330.txt | 1 +
arch/arm/boot/dts/rk3288.dtsi | 3 +
arch/arm/boot/dts/rk3xxx.dtsi | 3 +
drivers/dma/pl330.c | 101 +++++++++++++++------
4 files changed, 79 insertions(+), 29 deletions(-)
--
2.3.7
From: Boojin Kim <[email protected]>
This patch adds to support burst mode for dev-to-mem and
mem-to-dev transmit.
Signed-off-by: Boojin Kim <[email protected]>
Signed-off-by: Addy Ke <[email protected]>
Signed-off-by: Shawn Lin <[email protected]>
cc: Heiko Stuebner <[email protected]>
cc: Doug Anderson <[email protected]>
cc: Olof Johansson <[email protected]>
---
Changes in v2:
- amend the author
- amend Olof's mail address
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
- add From original author.
- remove Sunny's tag
drivers/dma/pl330.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index ecab4ea0..0d544d2 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -1141,10 +1141,13 @@ static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
+ enum pl330_cond cond;
+
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
while (cyc--) {
- off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
- off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
+ off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
+ off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_ST(dry_run, &buf[off], ALWAYS);
off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
}
@@ -1156,11 +1159,14 @@ static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
+ enum pl330_cond cond;
+
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
while (cyc--) {
- off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
+ off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_LD(dry_run, &buf[off], ALWAYS);
- off += _emit_STP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
+ off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
}
@@ -2557,7 +2563,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
desc->rqtype = direction;
desc->rqcfg.brst_size = pch->burst_sz;
- desc->rqcfg.brst_len = 1;
+ desc->rqcfg.brst_len = pch->burst_len;
desc->bytes_requested = period_len;
fill_px(&desc->px, dst, src, period_len);
@@ -2702,7 +2708,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}
desc->rqcfg.brst_size = pch->burst_sz;
- desc->rqcfg.brst_len = 1;
+ desc->rqcfg.brst_len = pch->burst_len;
desc->rqtype = direction;
desc->bytes_requested = sg_dma_len(sg);
}
--
2.3.7
From: Addy Ke <[email protected]>
This patch add "arm,pl330-broken-no-flushp" quirk to avoid execute
DMAFLUSHP if Soc doesn't support it.
Signed-off-by: Addy Ke <[email protected]>
Signed-off-by: Shawn Lin <[email protected]>
cc: Doug Anderson <[email protected]>
cc: Heiko Stuebner <[email protected]>
cc: Olof Johansson <[email protected]>
---
Changes in v2:
- amend the author
- amend Olof's mail address
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
- remove Sunny's tag
drivers/dma/pl330.c | 87 ++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 62 insertions(+), 25 deletions(-)
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 0d544d2..3b9b426 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -34,6 +34,8 @@
#define PL330_MAX_IRQS 32
#define PL330_MAX_PERI 32
+#define PL330_QUIRK_BROKEN_NO_FLUSHP BIT(0)
+
enum pl330_cachectrl {
CCTRL0, /* Noncacheable and nonbufferable */
CCTRL1, /* Bufferable only */
@@ -488,6 +490,17 @@ struct pl330_dmac {
/* Peripheral channels connected to this DMAC */
unsigned int num_peripherals;
struct dma_pl330_chan *peripherals; /* keep at end */
+ int quirks;
+};
+
+static struct pl330_of_quirks {
+ char *quirk;
+ int id;
+} of_quirks[] = {
+ {
+ .quirk = "arm,pl330-broken-no-flushp",
+ .id = PL330_QUIRK_BROKEN_NO_FLUSHP,
+ }
};
struct dma_pl330_desc {
@@ -1137,53 +1150,68 @@ static inline int _ldst_memtomem(unsigned dry_run, u8 buf[],
return off;
}
-static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
- const struct _xfer_spec *pxs, int cyc)
+static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run,
+ u8 buf[], const struct _xfer_spec *pxs,
+ int cyc)
{
int off = 0;
enum pl330_cond cond;
- cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
+ if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
+ cond = BURST;
+ else
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
while (cyc--) {
off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_ST(dry_run, &buf[off], ALWAYS);
- off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
+
+ if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
+ off += _emit_FLUSHP(dry_run, &buf[off],
+ pxs->desc->peri);
}
return off;
}
-static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
- const struct _xfer_spec *pxs, int cyc)
+static inline int _ldst_memtodev(struct pl330_dmac *pl330,
+ unsigned dry_run, u8 buf[],
+ const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
enum pl330_cond cond;
- cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
+ if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
+ cond = BURST;
+ else
+ cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
+
while (cyc--) {
off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
off += _emit_LD(dry_run, &buf[off], ALWAYS);
off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
- off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
+
+ if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
+ off += _emit_FLUSHP(dry_run, &buf[off],
+ pxs->desc->peri);
}
return off;
}
-static int _bursts(unsigned dry_run, u8 buf[],
+static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
const struct _xfer_spec *pxs, int cyc)
{
int off = 0;
switch (pxs->desc->rqtype) {
case DMA_MEM_TO_DEV:
- off += _ldst_memtodev(dry_run, &buf[off], pxs, cyc);
+ off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc);
break;
case DMA_DEV_TO_MEM:
- off += _ldst_devtomem(dry_run, &buf[off], pxs, cyc);
+ off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc);
break;
case DMA_MEM_TO_MEM:
off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc);
@@ -1197,7 +1225,7 @@ static int _bursts(unsigned dry_run, u8 buf[],
}
/* Returns bytes consumed and updates bursts */
-static inline int _loop(unsigned dry_run, u8 buf[],
+static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
unsigned long *bursts, const struct _xfer_spec *pxs)
{
int cyc, cycmax, szlp, szlpend, szbrst, off;
@@ -1220,7 +1248,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
}
szlp = _emit_LP(1, buf, 0, 0);
- szbrst = _bursts(1, buf, pxs, 1);
+ szbrst = _bursts(pl330, 1, buf, pxs, 1);
lpend.cond = ALWAYS;
lpend.forever = false;
@@ -1252,7 +1280,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
off += _emit_LP(dry_run, &buf[off], 1, lcnt1);
ljmp1 = off;
- off += _bursts(dry_run, &buf[off], pxs, cyc);
+ off += _bursts(pl330, dry_run, &buf[off], pxs, cyc);
lpend.cond = ALWAYS;
lpend.forever = false;
@@ -1275,8 +1303,9 @@ static inline int _loop(unsigned dry_run, u8 buf[],
return off;
}
-static inline int _setup_loops(unsigned dry_run, u8 buf[],
- const struct _xfer_spec *pxs)
+static inline int _setup_loops(struct pl330_dmac *pl330,
+ unsigned dry_run, u8 buf[],
+ const struct _xfer_spec *pxs)
{
struct pl330_xfer *x = &pxs->desc->px;
u32 ccr = pxs->ccr;
@@ -1285,15 +1314,16 @@ static inline int _setup_loops(unsigned dry_run, u8 buf[],
while (bursts) {
c = bursts;
- off += _loop(dry_run, &buf[off], &c, pxs);
+ off += _loop(pl330, dry_run, &buf[off], &c, pxs);
bursts -= c;
}
return off;
}
-static inline int _setup_xfer(unsigned dry_run, u8 buf[],
- const struct _xfer_spec *pxs)
+static inline int _setup_xfer(struct pl330_dmac *pl330,
+ unsigned dry_run, u8 buf[],
+ const struct _xfer_spec *pxs)
{
struct pl330_xfer *x = &pxs->desc->px;
int off = 0;
@@ -1304,7 +1334,7 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
off += _emit_MOV(dry_run, &buf[off], DAR, x->dst_addr);
/* Setup Loop(s) */
- off += _setup_loops(dry_run, &buf[off], pxs);
+ off += _setup_loops(pl330, dry_run, &buf[off], pxs);
return off;
}
@@ -1313,8 +1343,9 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
* A req is a sequence of one or more xfer units.
* Returns the number of bytes taken to setup the MC for the req.
*/
-static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
- unsigned index, struct _xfer_spec *pxs)
+static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run,
+ struct pl330_thread *thrd, unsigned index,
+ struct _xfer_spec *pxs)
{
struct _pl330_req *req = &thrd->req[index];
struct pl330_xfer *x;
@@ -1331,7 +1362,7 @@ static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
return -EINVAL;
- off += _setup_xfer(dry_run, &buf[off], pxs);
+ off += _setup_xfer(pl330, dry_run, &buf[off], pxs);
/* DMASEV peripheral/event */
off += _emit_SEV(dry_run, &buf[off], thrd->ev);
@@ -1425,7 +1456,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
xs.desc = desc;
/* First dry run to check if req is acceptable */
- ret = _setup_req(1, thrd, idx, &xs);
+ ret = _setup_req(pl330, 1, thrd, idx, &xs);
if (ret < 0)
goto xfer_exit;
@@ -1439,7 +1470,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
/* Hook the request */
thrd->lstenq = idx;
thrd->req[idx].desc = desc;
- _setup_req(0, thrd, idx, &xs);
+ _setup_req(pl330, 0, thrd, idx, &xs);
ret = 0;
@@ -2784,6 +2815,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
struct resource *res;
int i, ret, irq;
int num_chan;
+ struct device_node *np = adev->dev.of_node;
pdat = dev_get_platdata(&adev->dev);
@@ -2803,6 +2835,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
pl330->mcbufsz = pdat ? pdat->mcbuf_sz : 0;
+ /* get quirk */
+ for (i = 0; i < ARRAY_SIZE(of_quirks); i++)
+ if (of_property_read_bool(np, of_quirks[i].quirk))
+ pl330->quirks |= of_quirks[i].id;
+
res = &adev->res;
pl330->base = devm_ioremap_resource(&adev->dev, res);
if (IS_ERR(pl330->base))
--
2.3.7
Signed-off-by: Shawn Lin <[email protected]>
Reviewed-by: Doug Anderson <[email protected]>
---
Changes in v2:
- add Reviewed-by: Doug Anderson <[email protected]>
- reorder this patch before the usage of the quirk
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
Documentation/devicetree/bindings/dma/arm-pl330.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/dma/arm-pl330.txt b/Documentation/devicetree/bindings/dma/arm-pl330.txt
index 2675658..db7e226 100644
--- a/Documentation/devicetree/bindings/dma/arm-pl330.txt
+++ b/Documentation/devicetree/bindings/dma/arm-pl330.txt
@@ -15,6 +15,7 @@ Optional properties:
cells in the dmas property of client device.
- dma-channels: contains the total number of DMA channels supported by the DMAC
- dma-requests: contains the total number of DMA requests supported by the DMAC
+ - arm,pl330-broken-no-flushp: quirk for avoiding to execute DMAFLUSHP
Example:
--
2.3.7
From: Addy Ke <[email protected]>
Pl330 integrated in rk3288 platform doesn't support
DMAFLUSHP function. So we add arm,pl330-broken-no-flushp quirk
for it.
Signed-off-by: Addy Ke <[email protected]>
Signed-off-by: Shawn Lin <[email protected]>
cc: Heiko Stuebner <[email protected]>
cc: Olof Johansson <[email protected]>
Reviewed-by: Doug Anderson <[email protected]>
---
Changes in v2:
- amend the author
- add Reviewed-by: Doug Anderson <[email protected]>
- amend Olof's mail address
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
- remove Sunny's tag
arch/arm/boot/dts/rk3288.dtsi | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 22316d0..106adf7 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -144,6 +144,7 @@
#dma-cells = <1>;
clocks = <&cru ACLK_DMAC2>;
clock-names = "apb_pclk";
+ arm,pl330-broken-no-flushp;
};
dmac_bus_ns: dma-controller@ff600000 {
@@ -155,6 +156,7 @@
clocks = <&cru ACLK_DMAC1>;
clock-names = "apb_pclk";
status = "disabled";
+ arm,pl330-broken-no-flushp;
};
dmac_bus_s: dma-controller@ffb20000 {
@@ -165,6 +167,7 @@
#dma-cells = <1>;
clocks = <&cru ACLK_DMAC1>;
clock-names = "apb_pclk";
+ arm,pl330-broken-no-flushp;
};
};
--
2.3.7
Pl330 integrated in rk3xxx platform doesn't support
DMAFLUSHP function. So we add arm,pl330-broken-no-flushp quirk
for it.
Signed-off-by: Shawn Lin <[email protected]>
cc: Heiko Stuebner <[email protected]>
cc: Doug Anderson <[email protected]>
cc: Olof Johansson <[email protected]>
---
Changes in v2: None
Changes in v1:
- rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
by Krzysztof.
arch/arm/boot/dts/rk3xxx.dtsi | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm/boot/dts/rk3xxx.dtsi b/arch/arm/boot/dts/rk3xxx.dtsi
index a2ae9f3..a8ca4b3 100644
--- a/arch/arm/boot/dts/rk3xxx.dtsi
+++ b/arch/arm/boot/dts/rk3xxx.dtsi
@@ -79,6 +79,7 @@
#dma-cells = <1>;
clocks = <&cru ACLK_DMA1>;
clock-names = "apb_pclk";
+ arm,pl330-broken-no-flushp;
};
dmac1_ns: dma-controller@2001c000 {
@@ -89,6 +90,7 @@
#dma-cells = <1>;
clocks = <&cru ACLK_DMA1>;
clock-names = "apb_pclk";
+ arm,pl330-broken-no-flushp;
status = "disabled";
};
@@ -100,6 +102,7 @@
#dma-cells = <1>;
clocks = <&cru ACLK_DMA2>;
clock-names = "apb_pclk";
+ arm,pl330-broken-no-flushp;
};
};
--
2.3.7
On Thu, Aug 27, 2015 at 5:36 PM, Shawn Lin <[email protected]> wrote:
>
> The purpose of the DMAFLUSHP instruction:
> - Tell the peripheral to clear its status and control registers.
> - Send a message to the peripheral to resend its level status.
>
> There are 3 timings described in PL330 Technical Reference Manual:
> - Timing 1: Burst request, can work well without DMAFLUSHP.
> - Timing 2: Single and burst request, DMAC will ignore the single
> transfer request. This timing happens if there are single
> and burst request.
> - Timing 3: Single transfers for a burst request, DMAC should signals
> datype to request the peripheral to flush the contents of
> any control registers. This timing happens if there is
> not enough MFIFO to places the burst data.
>
> A peripheral may signal a DMA request during the execution of
> DMAFLUSHP instruction, that cause DMA request being ignored by DMAC.
>
> But DMAC and all peripherals on RK3X SoCs DO NOT support DMAFLUSHP.
> It can't send a message to the peripheral to resend DMA request,
> and the peripheral can't acknowledge a flush request from DMAC.
> So all DMA requests should NOT be ignored by DMAC, and DMAC will not
> notify the peripheral to flush.
>
> To fix this problem, we need:
> - Do NOT execute DMAFLUSHP instruction.
> - Timing 2 and timing 3 should not happen.
>
> Because on RK3X SoCs, there are 6 or below channels and 32 MFIFO depth
> for DMAC_BUS, and 8 channels and 64 MFIFO depth for DMAC_PERI, it is
> impossible to hit the timing 3 if burst length is equal or less than 4.
Fixing this issue also requires changes to drivers, so it would be
nice if you put those changes into the same patchset.
Otherwise someone may apply this series and expect things to work but
they will still be broken. Specifically the peripherals should be
setting their burst sizes for their DMA requests low enough to avoid
needing the working DMAFLUSHP instruction.
Also, I remember we ran into an issue when we tried using burst length
of 4 with the i2s device on RK3288 because we could get requests that
either weren't aligned or a multiple of 4 sizes and some transfers
would just fail, so we ended up using a burst size of 1. I recommend
if we aren't sure about size or alignment for a particular peripheral,
a burst size of 1 is safest. For something like a block device, I
think we can use the larger size bursts. That's another reason to
include the driver fixes in the series, just so we get it right,
thanks.
>
> Since the request type signal by the peripheral can only be set by
> software. We can set Rockchip Soc's GRF_PERIDMAC_CON0[2:1] to select single
> or burst request, if it is set b01, all of the peripharals will signal a brust
> request. So the timing 2 will not happen, too.
>
> So DMAC on RK3X can support single or burst transfer, but can't support
> mixed transfer.
>
> Because burst transfer is more efficient than single transfer, this is
> confirmed by our ASIC team, who strongly suggest to use burst transfer.
> And this is confirmed by Addy's test on RK3288-Pink2 board, the speed of
> spi flash burst transfer will increase about two times than single transfer.
> Also, I have tested dw_mmc with pl330 on RK3188 platform to double confirm
> the result. That means burst transfer is reansonable.
>
> So we need a quirk not to execute DMAFLUSHP instruction and to use burst
> transfer.
>
> Note:
> - The Rockchip Soc default value of GRF_PERIDMAC_CON0[2:1] is b01. To
> support brust transfer, these bits should not be changed in bootloader.
>
>
> Changes in v2:
> - amend the author
> - reorder the patches suggested by Doug
> - add Reviewed-by: Doug Anderson <[email protected]> for
> rk3288.dtsi patch and arm-pl330.txt patch
> - amend Olof's mail address
>
> Changes in v1:
> - rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
> by Krzysztof.
> - add From original author.
> - remove Sunny's tag
>
> Addy Ke (2):
> DMA: pl330: add quirk for broken no flushp
> ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3288 platform
>
> Boojin Kim (1):
> DMA: pl330: support burst mode for dev-to-mem and mem-to-dev transmit
>
> Shawn Lin (2):
> Documentation: arm-pl330: add description of
> arm,pl330-broken-no-flushp
> ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3xxx platform
>
> .../devicetree/bindings/dma/arm-pl330.txt | 1 +
> arch/arm/boot/dts/rk3288.dtsi | 3 +
> arch/arm/boot/dts/rk3xxx.dtsi | 3 +
> drivers/dma/pl330.c | 101 +++++++++++++++------
> 4 files changed, 79 insertions(+), 29 deletions(-)
>
> --
> 2.3.7
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
On Thu, Aug 27, 2015 at 5:38 PM, Shawn Lin <[email protected]> wrote:
> From: Addy Ke <[email protected]>
>
> This patch add "arm,pl330-broken-no-flushp" quirk to avoid execute
> DMAFLUSHP if Soc doesn't support it.
>
> Signed-off-by: Addy Ke <[email protected]>
> Signed-off-by: Shawn Lin <[email protected]>
> cc: Doug Anderson <[email protected]>
> cc: Heiko Stuebner <[email protected]>
> cc: Olof Johansson <[email protected]>
>
> ---
>
> Changes in v2:
> - amend the author
> - amend Olof's mail address
>
> Changes in v1:
> - rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
> by Krzysztof.
> - remove Sunny's tag
>
> drivers/dma/pl330.c | 87 ++++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 62 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index 0d544d2..3b9b426 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -34,6 +34,8 @@
> #define PL330_MAX_IRQS 32
> #define PL330_MAX_PERI 32
>
> +#define PL330_QUIRK_BROKEN_NO_FLUSHP BIT(0)
> +
> enum pl330_cachectrl {
> CCTRL0, /* Noncacheable and nonbufferable */
> CCTRL1, /* Bufferable only */
> @@ -488,6 +490,17 @@ struct pl330_dmac {
> /* Peripheral channels connected to this DMAC */
> unsigned int num_peripherals;
> struct dma_pl330_chan *peripherals; /* keep at end */
> + int quirks;
> +};
> +
> +static struct pl330_of_quirks {
> + char *quirk;
> + int id;
> +} of_quirks[] = {
> + {
> + .quirk = "arm,pl330-broken-no-flushp",
> + .id = PL330_QUIRK_BROKEN_NO_FLUSHP,
> + }
> };
>
> struct dma_pl330_desc {
> @@ -1137,53 +1150,68 @@ static inline int _ldst_memtomem(unsigned dry_run, u8 buf[],
> return off;
> }
>
> -static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
> - const struct _xfer_spec *pxs, int cyc)
> +static inline int _ldst_devtomem(struct pl330_dmac *pl330, unsigned dry_run,
> + u8 buf[], const struct _xfer_spec *pxs,
> + int cyc)
> {
> int off = 0;
> enum pl330_cond cond;
>
> - cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
> + if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
> + cond = BURST;
> + else
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
>
> while (cyc--) {
> off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_ST(dry_run, &buf[off], ALWAYS);
> - off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> +
> + if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
> + off += _emit_FLUSHP(dry_run, &buf[off],
> + pxs->desc->peri);
> }
>
> return off;
> }
>
> -static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
> - const struct _xfer_spec *pxs, int cyc)
> +static inline int _ldst_memtodev(struct pl330_dmac *pl330,
> + unsigned dry_run, u8 buf[],
> + const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
> enum pl330_cond cond;
>
> - cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
> + if (pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP)
> + cond = BURST;
> + else
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
> +
>
> while (cyc--) {
> off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_LD(dry_run, &buf[off], ALWAYS);
> off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
> - off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> +
> + if (!(pl330->quirks & PL330_QUIRK_BROKEN_NO_FLUSHP))
> + off += _emit_FLUSHP(dry_run, &buf[off],
> + pxs->desc->peri);
> }
>
> return off;
> }
>
> -static int _bursts(unsigned dry_run, u8 buf[],
> +static int _bursts(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
> const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
>
> switch (pxs->desc->rqtype) {
> case DMA_MEM_TO_DEV:
> - off += _ldst_memtodev(dry_run, &buf[off], pxs, cyc);
> + off += _ldst_memtodev(pl330, dry_run, &buf[off], pxs, cyc);
> break;
> case DMA_DEV_TO_MEM:
> - off += _ldst_devtomem(dry_run, &buf[off], pxs, cyc);
> + off += _ldst_devtomem(pl330, dry_run, &buf[off], pxs, cyc);
> break;
> case DMA_MEM_TO_MEM:
> off += _ldst_memtomem(dry_run, &buf[off], pxs, cyc);
> @@ -1197,7 +1225,7 @@ static int _bursts(unsigned dry_run, u8 buf[],
> }
>
> /* Returns bytes consumed and updates bursts */
> -static inline int _loop(unsigned dry_run, u8 buf[],
> +static inline int _loop(struct pl330_dmac *pl330, unsigned dry_run, u8 buf[],
> unsigned long *bursts, const struct _xfer_spec *pxs)
> {
> int cyc, cycmax, szlp, szlpend, szbrst, off;
> @@ -1220,7 +1248,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
> }
>
> szlp = _emit_LP(1, buf, 0, 0);
> - szbrst = _bursts(1, buf, pxs, 1);
> + szbrst = _bursts(pl330, 1, buf, pxs, 1);
>
> lpend.cond = ALWAYS;
> lpend.forever = false;
> @@ -1252,7 +1280,7 @@ static inline int _loop(unsigned dry_run, u8 buf[],
> off += _emit_LP(dry_run, &buf[off], 1, lcnt1);
> ljmp1 = off;
>
> - off += _bursts(dry_run, &buf[off], pxs, cyc);
> + off += _bursts(pl330, dry_run, &buf[off], pxs, cyc);
>
> lpend.cond = ALWAYS;
> lpend.forever = false;
> @@ -1275,8 +1303,9 @@ static inline int _loop(unsigned dry_run, u8 buf[],
> return off;
> }
>
> -static inline int _setup_loops(unsigned dry_run, u8 buf[],
> - const struct _xfer_spec *pxs)
> +static inline int _setup_loops(struct pl330_dmac *pl330,
> + unsigned dry_run, u8 buf[],
> + const struct _xfer_spec *pxs)
> {
> struct pl330_xfer *x = &pxs->desc->px;
> u32 ccr = pxs->ccr;
> @@ -1285,15 +1314,16 @@ static inline int _setup_loops(unsigned dry_run, u8 buf[],
>
> while (bursts) {
> c = bursts;
> - off += _loop(dry_run, &buf[off], &c, pxs);
> + off += _loop(pl330, dry_run, &buf[off], &c, pxs);
> bursts -= c;
> }
>
> return off;
> }
>
> -static inline int _setup_xfer(unsigned dry_run, u8 buf[],
> - const struct _xfer_spec *pxs)
> +static inline int _setup_xfer(struct pl330_dmac *pl330,
> + unsigned dry_run, u8 buf[],
> + const struct _xfer_spec *pxs)
> {
> struct pl330_xfer *x = &pxs->desc->px;
> int off = 0;
> @@ -1304,7 +1334,7 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
> off += _emit_MOV(dry_run, &buf[off], DAR, x->dst_addr);
>
> /* Setup Loop(s) */
> - off += _setup_loops(dry_run, &buf[off], pxs);
> + off += _setup_loops(pl330, dry_run, &buf[off], pxs);
>
> return off;
> }
> @@ -1313,8 +1343,9 @@ static inline int _setup_xfer(unsigned dry_run, u8 buf[],
> * A req is a sequence of one or more xfer units.
> * Returns the number of bytes taken to setup the MC for the req.
> */
> -static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
> - unsigned index, struct _xfer_spec *pxs)
> +static int _setup_req(struct pl330_dmac *pl330, unsigned dry_run,
> + struct pl330_thread *thrd, unsigned index,
> + struct _xfer_spec *pxs)
> {
> struct _pl330_req *req = &thrd->req[index];
> struct pl330_xfer *x;
> @@ -1331,7 +1362,7 @@ static int _setup_req(unsigned dry_run, struct pl330_thread *thrd,
> if (x->bytes % (BRST_SIZE(pxs->ccr) * BRST_LEN(pxs->ccr)))
> return -EINVAL;
>
> - off += _setup_xfer(dry_run, &buf[off], pxs);
> + off += _setup_xfer(pl330, dry_run, &buf[off], pxs);
>
> /* DMASEV peripheral/event */
> off += _emit_SEV(dry_run, &buf[off], thrd->ev);
> @@ -1425,7 +1456,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
> xs.desc = desc;
>
> /* First dry run to check if req is acceptable */
> - ret = _setup_req(1, thrd, idx, &xs);
> + ret = _setup_req(pl330, 1, thrd, idx, &xs);
> if (ret < 0)
> goto xfer_exit;
>
> @@ -1439,7 +1470,7 @@ static int pl330_submit_req(struct pl330_thread *thrd,
> /* Hook the request */
> thrd->lstenq = idx;
> thrd->req[idx].desc = desc;
> - _setup_req(0, thrd, idx, &xs);
> + _setup_req(pl330, 0, thrd, idx, &xs);
>
> ret = 0;
>
> @@ -2784,6 +2815,7 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
> struct resource *res;
> int i, ret, irq;
> int num_chan;
> + struct device_node *np = adev->dev.of_node;
>
> pdat = dev_get_platdata(&adev->dev);
>
> @@ -2803,6 +2835,11 @@ pl330_probe(struct amba_device *adev, const struct amba_id *id)
>
> pl330->mcbufsz = pdat ? pdat->mcbuf_sz : 0;
>
> + /* get quirk */
> + for (i = 0; i < ARRAY_SIZE(of_quirks); i++)
> + if (of_property_read_bool(np, of_quirks[i].quirk))
> + pl330->quirks |= of_quirks[i].id;
> +
> res = &adev->res;
> pl330->base = devm_ioremap_resource(&adev->dev, res);
> if (IS_ERR(pl330->base))
> --
> 2.3.7
>
Reviewed-by: Sonny Rao <[email protected]>
>
>
> _______________________________________________
> Linux-rockchip mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-rockchip
On Thu, Aug 27, 2015 at 5:37 PM, Shawn Lin <[email protected]> wrote:
> From: Boojin Kim <[email protected]>
>
> This patch adds to support burst mode for dev-to-mem and
> mem-to-dev transmit.
>
> Signed-off-by: Boojin Kim <[email protected]>
> Signed-off-by: Addy Ke <[email protected]>
> Signed-off-by: Shawn Lin <[email protected]>
> cc: Heiko Stuebner <[email protected]>
> cc: Doug Anderson <[email protected]>
> cc: Olof Johansson <[email protected]>
>
> ---
>
> Changes in v2:
> - amend the author
> - amend Olof's mail address
>
> Changes in v1:
> - rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
> by Krzysztof.
> - add From original author.
> - remove Sunny's tag
>
> drivers/dma/pl330.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
> index ecab4ea0..0d544d2 100644
> --- a/drivers/dma/pl330.c
> +++ b/drivers/dma/pl330.c
> @@ -1141,10 +1141,13 @@ static inline int _ldst_devtomem(unsigned dry_run, u8 buf[],
> const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
> + enum pl330_cond cond;
> +
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
>
> while (cyc--) {
> - off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> - off += _emit_LDP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> + off += _emit_LDP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_ST(dry_run, &buf[off], ALWAYS);
> off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> }
> @@ -1156,11 +1159,14 @@ static inline int _ldst_memtodev(unsigned dry_run, u8 buf[],
> const struct _xfer_spec *pxs, int cyc)
> {
> int off = 0;
> + enum pl330_cond cond;
> +
> + cond = (pxs->desc->rqcfg.brst_len == 1) ? SINGLE : BURST;
>
> while (cyc--) {
> - off += _emit_WFP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_WFP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_LD(dry_run, &buf[off], ALWAYS);
> - off += _emit_STP(dry_run, &buf[off], SINGLE, pxs->desc->peri);
> + off += _emit_STP(dry_run, &buf[off], cond, pxs->desc->peri);
> off += _emit_FLUSHP(dry_run, &buf[off], pxs->desc->peri);
> }
>
> @@ -2557,7 +2563,7 @@ static struct dma_async_tx_descriptor *pl330_prep_dma_cyclic(
>
> desc->rqtype = direction;
> desc->rqcfg.brst_size = pch->burst_sz;
> - desc->rqcfg.brst_len = 1;
> + desc->rqcfg.brst_len = pch->burst_len;
> desc->bytes_requested = period_len;
> fill_px(&desc->px, dst, src, period_len);
>
> @@ -2702,7 +2708,7 @@ pl330_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
> }
>
> desc->rqcfg.brst_size = pch->burst_sz;
> - desc->rqcfg.brst_len = 1;
> + desc->rqcfg.brst_len = pch->burst_len;
> desc->rqtype = direction;
> desc->bytes_requested = sg_dma_len(sg);
> }
> --
> 2.3.7
Reviewed-by: Sonny Rao <[email protected]>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
On Thu, Aug 27, 2015 at 5:38 PM, Shawn Lin <[email protected]> wrote:
> Signed-off-by: Shawn Lin <[email protected]>
> Reviewed-by: Doug Anderson <[email protected]>
> ---
>
> Changes in v2:
> - add Reviewed-by: Doug Anderson <[email protected]>
> - reorder this patch before the usage of the quirk
>
> Changes in v1:
> - rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
> by Krzysztof.
>
> Documentation/devicetree/bindings/dma/arm-pl330.txt | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/Documentation/devicetree/bindings/dma/arm-pl330.txt b/Documentation/devicetree/bindings/dma/arm-pl330.txt
> index 2675658..db7e226 100644
> --- a/Documentation/devicetree/bindings/dma/arm-pl330.txt
> +++ b/Documentation/devicetree/bindings/dma/arm-pl330.txt
> @@ -15,6 +15,7 @@ Optional properties:
> cells in the dmas property of client device.
> - dma-channels: contains the total number of DMA channels supported by the DMAC
> - dma-requests: contains the total number of DMA requests supported by the DMAC
> + - arm,pl330-broken-no-flushp: quirk for avoiding to execute DMAFLUSHP
>
> Example:
>
> --
> 2.3.7
Reviewed-by: Sonny Rao <[email protected]>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
在 2015/9/1 5:40, Sonny Rao 写道:
> On Thu, Aug 27, 2015 at 5:36 PM, Shawn Lin <[email protected]> wrote:
>>
>> The purpose of the DMAFLUSHP instruction:
>> - Tell the peripheral to clear its status and control registers.
>> - Send a message to the peripheral to resend its level status.
>>
>> There are 3 timings described in PL330 Technical Reference Manual:
>> - Timing 1: Burst request, can work well without DMAFLUSHP.
>> - Timing 2: Single and burst request, DMAC will ignore the single
>> transfer request. This timing happens if there are single
>> and burst request.
>> - Timing 3: Single transfers for a burst request, DMAC should signals
>> datype to request the peripheral to flush the contents of
>> any control registers. This timing happens if there is
>> not enough MFIFO to places the burst data.
>>
>> A peripheral may signal a DMA request during the execution of
>> DMAFLUSHP instruction, that cause DMA request being ignored by DMAC.
>>
>> But DMAC and all peripherals on RK3X SoCs DO NOT support DMAFLUSHP.
>> It can't send a message to the peripheral to resend DMA request,
>> and the peripheral can't acknowledge a flush request from DMAC.
>> So all DMA requests should NOT be ignored by DMAC, and DMAC will not
>> notify the peripheral to flush.
>>
>> To fix this problem, we need:
>> - Do NOT execute DMAFLUSHP instruction.
>> - Timing 2 and timing 3 should not happen.
>>
>> Because on RK3X SoCs, there are 6 or below channels and 32 MFIFO depth
>> for DMAC_BUS, and 8 channels and 64 MFIFO depth for DMAC_PERI, it is
>> impossible to hit the timing 3 if burst length is equal or less than 4.
>
> Fixing this issue also requires changes to drivers, so it would be
> nice if you put those changes into the same patchset.
> Otherwise someone may apply this series and expect things to work but
> they will still be broken. Specifically the peripherals should be
> setting their burst sizes for their DMA requests low enough to avoid
> needing the working DMAFLUSHP instruction.
>
> Also, I remember we ran into an issue when we tried using burst length
> of 4 with the i2s device on RK3288 because we could get requests that
> either weren't aligned or a multiple of 4 sizes and some transfers
> would just fail, so we ended up using a burst size of 1. I recommend
> if we aren't sure about size or alignment for a particular peripheral,
> a burst size of 1 is safest. For something like a block device, I
> think we can use the larger size bursts. That's another reason to
Agreed. Those changes will be added in v3.
Thanks, Sunny.
> include the driver fixes in the series, just so we get it right,
> thanks.
>
>>
>> Since the request type signal by the peripheral can only be set by
>> software. We can set Rockchip Soc's GRF_PERIDMAC_CON0[2:1] to select single
>> or burst request, if it is set b01, all of the peripharals will signal a brust
>> request. So the timing 2 will not happen, too.
>>
>> So DMAC on RK3X can support single or burst transfer, but can't support
>> mixed transfer.
>>
>> Because burst transfer is more efficient than single transfer, this is
>> confirmed by our ASIC team, who strongly suggest to use burst transfer.
>> And this is confirmed by Addy's test on RK3288-Pink2 board, the speed of
>> spi flash burst transfer will increase about two times than single transfer.
>> Also, I have tested dw_mmc with pl330 on RK3188 platform to double confirm
>> the result. That means burst transfer is reansonable.
>>
>> So we need a quirk not to execute DMAFLUSHP instruction and to use burst
>> transfer.
>>
>> Note:
>> - The Rockchip Soc default value of GRF_PERIDMAC_CON0[2:1] is b01. To
>> support brust transfer, these bits should not be changed in bootloader.
>>
>>
>> Changes in v2:
>> - amend the author
>> - reorder the patches suggested by Doug
>> - add Reviewed-by: Doug Anderson <[email protected]> for
>> rk3288.dtsi patch and arm-pl330.txt patch
>> - amend Olof's mail address
>>
>> Changes in v1:
>> - rename broken-no-flushp to "arm,pl330-broken-no-flushp" suggested
>> by Krzysztof.
>> - add From original author.
>> - remove Sunny's tag
>>
>> Addy Ke (2):
>> DMA: pl330: add quirk for broken no flushp
>> ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3288 platform
>>
>> Boojin Kim (1):
>> DMA: pl330: support burst mode for dev-to-mem and mem-to-dev transmit
>>
>> Shawn Lin (2):
>> Documentation: arm-pl330: add description of
>> arm,pl330-broken-no-flushp
>> ARM: dts: Add arm,pl330-broken-no-flushp quirk for rk3xxx platform
>>
>> .../devicetree/bindings/dma/arm-pl330.txt | 1 +
>> arch/arm/boot/dts/rk3288.dtsi | 3 +
>> arch/arm/boot/dts/rk3xxx.dtsi | 3 +
>> drivers/dma/pl330.c | 101 +++++++++++++++------
>> 4 files changed, 79 insertions(+), 29 deletions(-)
>>
>> --
>> 2.3.7
>>
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
>> the body of a message to [email protected]
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at http://www.tux.org/lkml/
>
>
>
--
Best Regards
Shawn Lin