From: Fugang Duan <[email protected]>
iMX8 fuse word index represent as one 4-bytes word,
it should not be divided by 4.
Exp:
- MAC0 address layout in fuse:
offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
offset 709: XX xx MAC[5] MAC[4]
Signed-off-by: Fugang Duan <[email protected]>
---
drivers/nvmem/imx-ocotp-scu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
index d9dc482..be2f5f0 100644
--- a/drivers/nvmem/imx-ocotp-scu.c
+++ b/drivers/nvmem/imx-ocotp-scu.c
@@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
void *p;
int i, ret;
- index = offset >> 2;
- num_bytes = round_up((offset % 4) + bytes, 4);
+ index = offset;
+ num_bytes = round_up(bytes, 4);
count = num_bytes >> 2;
if (count > (priv->data->nregs - index))
@@ -100,7 +100,7 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
buf++;
}
- memcpy(val, (u8 *)p + offset % 4, bytes);
+ memcpy(val, (u8 *)p, bytes);
kfree(p);
--
2.7.4
Hi,
On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> From: Fugang Duan <[email protected]>
>
> iMX8 fuse word index represent as one 4-bytes word,
> it should not be divided by 4.
>
> Exp:
> - MAC0 address layout in fuse:
> offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> offset 709: XX xx MAC[5] MAC[4]
>
> Signed-off-by: Fugang Duan <[email protected]>
> ---
> drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
> index d9dc482..be2f5f0 100644
> --- a/drivers/nvmem/imx-ocotp-scu.c
> +++ b/drivers/nvmem/imx-ocotp-scu.c
> @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
> void *p;
> int i, ret;
>
> - index = offset >> 2;
> - num_bytes = round_up((offset % 4) + bytes, 4);
> + index = offset;
> + num_bytes = round_up(bytes, 4);
> count = num_bytes >> 2;
>
> if (count > (priv->data->nregs - index))
> @@ -100,7 +100,7 @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
> buf++;
> }
>
> - memcpy(val, (u8 *)p + offset % 4, bytes);
> + memcpy(val, (u8 *)p, bytes);
>
> kfree(p);
>
With these changes you could use the 'val' pointer directly
as the destination for ocotp_read() without need for an intermediate
buffer.
Lothar Waßmann
From: Lothar Waßmann <[email protected]> Sent: Thursday, July 4, 2019 11:46 PM
> Hi,
>
> On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> > From: Fugang Duan <[email protected]>
> >
> > iMX8 fuse word index represent as one 4-bytes word, it should not be
> > divided by 4.
> >
> > Exp:
> > - MAC0 address layout in fuse:
> > offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> > offset 709: XX xx MAC[5] MAC[4]
> >
> > Signed-off-by: Fugang Duan <[email protected]>
> > ---
> > drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/nvmem/imx-ocotp-scu.c
> > b/drivers/nvmem/imx-ocotp-scu.c index d9dc482..be2f5f0 100644
> > --- a/drivers/nvmem/imx-ocotp-scu.c
> > +++ b/drivers/nvmem/imx-ocotp-scu.c
> > @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context, unsigned
> int offset,
> > void *p;
> > int i, ret;
> >
> > - index = offset >> 2;
> > - num_bytes = round_up((offset % 4) + bytes, 4);
> > + index = offset;
> > + num_bytes = round_up(bytes, 4);
> > count = num_bytes >> 2;
> >
> > if (count > (priv->data->nregs - index)) @@ -100,7 +100,7 @@
> > static int imx_scu_ocotp_read(void *context, unsigned int offset,
> > buf++;
> > }
> >
> > - memcpy(val, (u8 *)p + offset % 4, bytes);
> > + memcpy(val, (u8 *)p, bytes);
> >
> > kfree(p);
> >
> With these changes you could use the 'val' pointer directly as the destination
> for ocotp_read() without need for an intermediate buffer.
>
>
> Lothar Waßmann
You are right, in fact, we can remove "p" and "buf" pointer.
Thanks for your review, I will send out the V2.
From: Andy Duan Sent: Friday, July 5, 2019 12:08 AM
> From: Lothar Waßmann <[email protected]> Sent: Thursday, July 4,
> 2019 11:46 PM
> > Hi,
> >
> > On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> > > From: Fugang Duan <[email protected]>
> > >
> > > iMX8 fuse word index represent as one 4-bytes word, it should not be
> > > divided by 4.
> > >
> > > Exp:
> > > - MAC0 address layout in fuse:
> > > offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> > > offset 709: XX xx MAC[5] MAC[4]
> > >
> > > Signed-off-by: Fugang Duan <[email protected]>
> > > ---
> > > drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/nvmem/imx-ocotp-scu.c
> > > b/drivers/nvmem/imx-ocotp-scu.c index d9dc482..be2f5f0 100644
> > > --- a/drivers/nvmem/imx-ocotp-scu.c
> > > +++ b/drivers/nvmem/imx-ocotp-scu.c
> > > @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context,
> > > unsigned
> > int offset,
> > > void *p;
> > > int i, ret;
> > >
> > > - index = offset >> 2;
> > > - num_bytes = round_up((offset % 4) + bytes, 4);
> > > + index = offset;
> > > + num_bytes = round_up(bytes, 4);
> > > count = num_bytes >> 2;
> > >
> > > if (count > (priv->data->nregs - index)) @@ -100,7 +100,7 @@
> > > static int imx_scu_ocotp_read(void *context, unsigned int offset,
> > > buf++;
> > > }
> > >
> > > - memcpy(val, (u8 *)p + offset % 4, bytes);
> > > + memcpy(val, (u8 *)p, bytes);
> > >
> > > kfree(p);
> > >
> > With these changes you could use the 'val' pointer directly as the
> > destination for ocotp_read() without need for an intermediate buffer.
> >
> >
> > Lothar Waßmann
>
> You are right, in fact, we can remove "p" and "buf" pointer.
> Thanks for your review, I will send out the V2.
Hi Lothar,
It still need intermediate buffer to read out n words (n * 4 bytes) from eFuse.
Because 'val' buffer size is real count parsed from DT, which is not an integer multiple of 4.
For example, cell->bytes is parsed from "reg" property and it is real count like 6.
fec_mac0: mac@2c4 {
reg = <0x2c4 6>;
};
So we have to use intermediate buffer here.
Hi,
On Fri, 5 Jul 2019 02:46:32 +0000 Andy Duan wrote:
> From: Andy Duan Sent: Friday, July 5, 2019 12:08 AM
> > From: Lothar Waßmann <[email protected]> Sent: Thursday, July 4,
> > 2019 11:46 PM
> > > Hi,
> > >
> > > On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> > > > From: Fugang Duan <[email protected]>
> > > >
> > > > iMX8 fuse word index represent as one 4-bytes word, it should not be
> > > > divided by 4.
> > > >
> > > > Exp:
> > > > - MAC0 address layout in fuse:
> > > > offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> > > > offset 709: XX xx MAC[5] MAC[4]
> > > >
> > > > Signed-off-by: Fugang Duan <[email protected]>
> > > > ---
> > > > drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> > > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/nvmem/imx-ocotp-scu.c
> > > > b/drivers/nvmem/imx-ocotp-scu.c index d9dc482..be2f5f0 100644
> > > > --- a/drivers/nvmem/imx-ocotp-scu.c
> > > > +++ b/drivers/nvmem/imx-ocotp-scu.c
> > > > @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context,
> > > > unsigned
> > > int offset,
> > > > void *p;
> > > > int i, ret;
> > > >
> > > > - index = offset >> 2;
> > > > - num_bytes = round_up((offset % 4) + bytes, 4);
> > > > + index = offset;
> > > > + num_bytes = round_up(bytes, 4);
> > > > count = num_bytes >> 2;
> > > >
> > > > if (count > (priv->data->nregs - index)) @@ -100,7 +100,7 @@
> > > > static int imx_scu_ocotp_read(void *context, unsigned int offset,
> > > > buf++;
> > > > }
> > > >
> > > > - memcpy(val, (u8 *)p + offset % 4, bytes);
> > > > + memcpy(val, (u8 *)p, bytes);
> > > >
> > > > kfree(p);
> > > >
> > > With these changes you could use the 'val' pointer directly as the
> > > destination for ocotp_read() without need for an intermediate buffer.
> > >
> > >
> > > Lothar Waßmann
> >
> > You are right, in fact, we can remove "p" and "buf" pointer.
> > Thanks for your review, I will send out the V2.
>
> Hi Lothar,
>
> It still need intermediate buffer to read out n words (n * 4 bytes) from eFuse.
> Because 'val' buffer size is real count parsed from DT, which is not an integer multiple of 4.
>
> For example, cell->bytes is parsed from "reg" property and it is real count like 6.
> fec_mac0: mac@2c4 {
> reg = <0x2c4 6>;
> };
>
> So we have to use intermediate buffer here.
>
val is a u32 pointer, so legally it cannot point to any buffer whose
size is not divisible by four!
Lothar Waßmann
From: Lothar Waßmann <[email protected]> Sent: Friday, July 5, 2019 3:13 PM
> Hi,
>
> On Fri, 5 Jul 2019 02:46:32 +0000 Andy Duan wrote:
> > From: Andy Duan Sent: Friday, July 5, 2019 12:08 AM
> > > From: Lothar Waßmann <[email protected]> Sent: Thursday, July
> > > 4,
> > > 2019 11:46 PM
> > > > Hi,
> > > >
> > > > On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> > > > > From: Fugang Duan <[email protected]>
> > > > >
> > > > > iMX8 fuse word index represent as one 4-bytes word, it should
> > > > > not be divided by 4.
> > > > >
> > > > > Exp:
> > > > > - MAC0 address layout in fuse:
> > > > > offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> > > > > offset 709: XX xx MAC[5] MAC[4]
> > > > >
> > > > > Signed-off-by: Fugang Duan <[email protected]>
> > > > > ---
> > > > > drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> > > > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > > > >
> > > > > diff --git a/drivers/nvmem/imx-ocotp-scu.c
> > > > > b/drivers/nvmem/imx-ocotp-scu.c index d9dc482..be2f5f0 100644
> > > > > --- a/drivers/nvmem/imx-ocotp-scu.c
> > > > > +++ b/drivers/nvmem/imx-ocotp-scu.c
> > > > > @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context,
> > > > > unsigned
> > > > int offset,
> > > > > void *p;
> > > > > int i, ret;
> > > > >
> > > > > - index = offset >> 2;
> > > > > - num_bytes = round_up((offset % 4) + bytes, 4);
> > > > > + index = offset;
> > > > > + num_bytes = round_up(bytes, 4);
> > > > > count = num_bytes >> 2;
> > > > >
> > > > > if (count > (priv->data->nregs - index)) @@ -100,7 +100,7
> > > > > @@ static int imx_scu_ocotp_read(void *context, unsigned int offset,
> > > > > buf++;
> > > > > }
> > > > >
> > > > > - memcpy(val, (u8 *)p + offset % 4, bytes);
> > > > > + memcpy(val, (u8 *)p, bytes);
> > > > >
> > > > > kfree(p);
> > > > >
> > > > With these changes you could use the 'val' pointer directly as the
> > > > destination for ocotp_read() without need for an intermediate buffer.
> > > >
> > > >
> > > > Lothar Waßmann
> > >
> > > You are right, in fact, we can remove "p" and "buf" pointer.
> > > Thanks for your review, I will send out the V2.
> >
> > Hi Lothar,
> >
> > It still need intermediate buffer to read out n words (n * 4 bytes) from
> eFuse.
> > Because 'val' buffer size is real count parsed from DT, which is not an integer
> multiple of 4.
> >
> > For example, cell->bytes is parsed from "reg" property and it is real count
> like 6.
> > fec_mac0: mac@2c4 {
> > reg = <0x2c4 6>;
> > };
> >
> > So we have to use intermediate buffer here.
> >
> val is a u32 pointer, so legally it cannot point to any buffer whose size is not
> divisible by four!
>
Yes, val is a u32 pointer, as my understand, it point to the 'buf' whose size is cell->bytes
(the size is not parsed from 'reg' property)
The piece of code:
buf = kzalloc(cell->bytes, GFP_KERNEL);
nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
imx_scu_ocotp_read(void *context, unsigned int offset, void *val, size_t bytes);
If so, we still need intermediate buffer to read out eFuse words, and copy 'cell->bytes'
bytes to 'val' buffer.
May I understand wrong ? Thanks very much!
From: Andy Duan Sent: Friday, July 5, 2019 3:33 PM
> From: Lothar Waßmann <[email protected]> Sent: Friday, July 5, 2019
> 3:13 PM
> > Hi,
> >
> > On Fri, 5 Jul 2019 02:46:32 +0000 Andy Duan wrote:
> > > From: Andy Duan Sent: Friday, July 5, 2019 12:08 AM
> > > > From: Lothar Waßmann <[email protected]> Sent: Thursday,
> July
> > > > 4,
> > > > 2019 11:46 PM
> > > > > Hi,
> > > > >
> > > > > On Thu, 4 Jul 2019 22:20:15 +0800 [email protected] wrote:
> > > > > > From: Fugang Duan <[email protected]>
> > > > > >
> > > > > > iMX8 fuse word index represent as one 4-bytes word, it should
> > > > > > not be divided by 4.
> > > > > >
> > > > > > Exp:
> > > > > > - MAC0 address layout in fuse:
> > > > > > offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> > > > > > offset 709: XX xx MAC[5] MAC[4]
> > > > > >
> > > > > > Signed-off-by: Fugang Duan <[email protected]>
> > > > > > ---
> > > > > > drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> > > > > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/nvmem/imx-ocotp-scu.c
> > > > > > b/drivers/nvmem/imx-ocotp-scu.c index d9dc482..be2f5f0 100644
> > > > > > --- a/drivers/nvmem/imx-ocotp-scu.c
> > > > > > +++ b/drivers/nvmem/imx-ocotp-scu.c
> > > > > > @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context,
> > > > > > unsigned
> > > > > int offset,
> > > > > > void *p;
> > > > > > int i, ret;
> > > > > >
> > > > > > - index = offset >> 2;
> > > > > > - num_bytes = round_up((offset % 4) + bytes, 4);
> > > > > > + index = offset;
> > > > > > + num_bytes = round_up(bytes, 4);
> > > > > > count = num_bytes >> 2;
> > > > > >
> > > > > > if (count > (priv->data->nregs - index)) @@ -100,7
> > > > > > +100,7 @@ static int imx_scu_ocotp_read(void *context, unsigned
> int offset,
> > > > > > buf++;
> > > > > > }
> > > > > >
> > > > > > - memcpy(val, (u8 *)p + offset % 4, bytes);
> > > > > > + memcpy(val, (u8 *)p, bytes);
> > > > > >
> > > > > > kfree(p);
> > > > > >
> > > > > With these changes you could use the 'val' pointer directly as
> > > > > the destination for ocotp_read() without need for an intermediate
> buffer.
> > > > >
> > > > >
> > > > > Lothar Waßmann
> > > >
> > > > You are right, in fact, we can remove "p" and "buf" pointer.
> > > > Thanks for your review, I will send out the V2.
> > >
> > > Hi Lothar,
> > >
> > > It still need intermediate buffer to read out n words (n * 4 bytes)
> > > from
> > eFuse.
> > > Because 'val' buffer size is real count parsed from DT, which is not
> > > an integer
> > multiple of 4.
> > >
> > > For example, cell->bytes is parsed from "reg" property and it is
> > > real count
> > like 6.
> > > fec_mac0: mac@2c4 {
> > > reg = <0x2c4 6>;
> > > };
> > >
> > > So we have to use intermediate buffer here.
> > >
> > val is a u32 pointer, so legally it cannot point to any buffer whose
> > size is not divisible by four!
> >
> Yes, val is a u32 pointer, as my understand, it point to the 'buf' whose size is
> cell->bytes (the size is not parsed from 'reg' property)
>
> The piece of code:
> buf = kzalloc(cell->bytes, GFP_KERNEL);
> nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
> imx_scu_ocotp_read(void *context, unsigned int offset, void *val, size_t
> bytes);
>
> If so, we still need intermediate buffer to read out eFuse words, and copy
> 'cell->bytes'
> bytes to 'val' buffer.
> May I understand wrong ? Thanks very much!
Lothar, any comment ? Thanks !
Ping ...
> From: Fugang Duan <[email protected]>
>
> iMX8 fuse word index represent as one 4-bytes word, it should not be divided
> by 4.
>
> Exp:
> - MAC0 address layout in fuse:
> offset 708: MAC[3] MAC[2] MAC[1] MAC[0]
> offset 709: XX xx MAC[5] MAC[4]
>
> Signed-off-by: Fugang Duan <[email protected]>
> ---
> drivers/nvmem/imx-ocotp-scu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/nvmem/imx-ocotp-scu.c b/drivers/nvmem/imx-ocotp-scu.c
> index d9dc482..be2f5f0 100644
> --- a/drivers/nvmem/imx-ocotp-scu.c
> +++ b/drivers/nvmem/imx-ocotp-scu.c
> @@ -71,8 +71,8 @@ static int imx_scu_ocotp_read(void *context, unsigned
> int offset,
> void *p;
> int i, ret;
>
> - index = offset >> 2;
> - num_bytes = round_up((offset % 4) + bytes, 4);
> + index = offset;
> + num_bytes = round_up(bytes, 4);
> count = num_bytes >> 2;
>
> if (count > (priv->data->nregs - index)) @@ -100,7 +100,7 @@ static int
> imx_scu_ocotp_read(void *context, unsigned int offset,
> buf++;
> }
>
> - memcpy(val, (u8 *)p + offset % 4, bytes);
> + memcpy(val, (u8 *)p, bytes);
>
> kfree(p);
>
> --
> 2.7.4