| Message ID | 20190704142015.10701-1-fugang.duan@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [nvmem,1/1] nvmem: imx: correct the fuse word index | expand |
Hi, On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > From: Fugang Duan <fugang.duan@nxp.com> > > 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 <fugang.duan@nxp.com> > --- > 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 <LW@KARO-electronics.de> Sent: Thursday, July 4, 2019 11:46 PM > Hi, > > On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > > From: Fugang Duan <fugang.duan@nxp.com> > > > > 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 <fugang.duan@nxp.com> > > --- > > 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 <LW@KARO-electronics.de> Sent: Thursday, July 4, > 2019 11:46 PM > > Hi, > > > > On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > > > From: Fugang Duan <fugang.duan@nxp.com> > > > > > > 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 <fugang.duan@nxp.com> > > > --- > > > 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 <LW@KARO-electronics.de> Sent: Thursday, July 4, > > 2019 11:46 PM > > > Hi, > > > > > > On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > > > > From: Fugang Duan <fugang.duan@nxp.com> > > > > > > > > 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 <fugang.duan@nxp.com> > > > > --- > > > > 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 <LW@KARO-electronics.de> 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 <LW@KARO-electronics.de> Sent: Thursday, July > > > 4, > > > 2019 11:46 PM > > > > Hi, > > > > > > > > On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > > > > > From: Fugang Duan <fugang.duan@nxp.com> > > > > > > > > > > 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 <fugang.duan@nxp.com> > > > > > --- > > > > > 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 <LW@KARO-electronics.de> 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 <LW@KARO-electronics.de> Sent: Thursday, > July > > > > 4, > > > > 2019 11:46 PM > > > > > Hi, > > > > > > > > > > On Thu, 4 Jul 2019 22:20:15 +0800 fugang.duan@nxp.com wrote: > > > > > > From: Fugang Duan <fugang.duan@nxp.com> > > > > > > > > > > > > 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 <fugang.duan@nxp.com> > > > > > > --- > > > > > > 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 <fugang.duan@nxp.com> > > 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 <fugang.duan@nxp.com> > --- > 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
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);