All,
has anybody made some investigations about performance of a SD/MMC card
on SPI ?
Actually I'm using various cards (different speed classes) on an SPI bus
of a MPC8343 cpu.
Everything is working fine basically, i.e. card is detected properly and
block device can be mounted and used.
SPI clock is adjusted to the card's capabilities and is running quite
fast (>30MHz).
But between consecutive reads/writes there's a fixed gap of 2us thus
yielding a poor performance of approx. 300KBytes/sec.
The spi bus is utilized only ~10%.
Any ideas where this comes from ?
Ist it a fixed delay regarding to some kind of spec or is it possibly a
spi driver/mmc layer issue ?
regards,
Andre Schwarz
MATRIX VISION GmbH, Talstraße 16, DE-71570 Oppenweiler - Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschäftsführer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
Hello,
I am trying to enable the SD over SPI on a emebedded system with one
processor powerpc mpc5200b; you have enabled mmc over spi into a native
spi or psc spi?
regards,
Fabio
Andre Schwarz ha scritto:
All,
has anybody made some investigations about performance of a SD/MMC card
on SPI ?
Actually I'm using various cards (different speed classes) on an SPI bus
of a MPC8343 cpu.
Everything is working fine basically, i.e. card is detected properly and
block device can be mounted and used.
SPI clock is adjusted to the card's capabilities and is running quite
fast (>30MHz).
But between consecutive reads/writes there's a fixed gap of 2us thus
yielding a poor performance of approx. 300KBytes/sec.
The spi bus is utilized only ~10%.
Any ideas where this comes from ?
Ist it a fixed delay regarding to some kind of spec or is it possibly a
spi driver/mmc layer issue ?
regards,
Andre Schwarz
MATRIX VISION GmbH, Talstraße 16, DE-71570 Oppenweiler - Registergericht: Amtsgericht Stuttgart, HRB 271090
Geschäftsführer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
.
Fabio,
I'm running on a MPC8343.
The SD-Card is connected on the spi hardware controller.
regards,
Andr=E9
Fabio Tosetto schrieb:
Hello,
=20
I am trying to enable the SD over SPI on a emebedded system with one
processor powerpc mpc5200b; you have enabled mmc over spi into a native=
=20
spi or psc spi?
=20
regards,
Fabio
=20
Andre Schwarz ha scritto:
quoted
All,
has anybody made some investigations about performance of a SD/MMC car=
d
quoted
on SPI ?
Actually I'm using various cards (different speed classes) on an SPI b=
us
quoted
of a MPC8343 cpu.
Everything is working fine basically, i.e. card is detected properly a=
nd
quoted
block device can be mounted and used.
SPI clock is adjusted to the card's capabilities and is running quite
fast (>30MHz).
But between consecutive reads/writes there's a fixed gap of 2us thus
yielding a poor performance of approx. 300KBytes/sec.
The spi bus is utilized only ~10%.
Any ideas where this comes from ?
Ist it a fixed delay regarding to some kind of spec or is it possibly =
a
quoted
spi driver/mmc layer issue ?
regards,
Andre Schwarz
MATRIX VISION GmbH, Talstra=DFe 16, DE-71570 Oppenweiler -=20
Registergericht: Amtsgericht Stuttgart, HRB 271090
Gesch=E4ftsf=FChrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
.
=20
=20
MATRIX VISION GmbH, Talstra=DFe 16, DE-71570 Oppenweiler - Registergeric=
ht: Amtsgericht Stuttgart, HRB 271090
Gesch=E4ftsf=FChrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner