| Message ID | f8708ea925142bc365458ee3b9a0edaae2e88d22.1448602470.git.crosthwaite.peter@gmail.com |
|---|---|
| State | New |
| Headers | show |
> -----Original Message----- > From: Peter Crosthwaite [mailto:crosthwaitepeter@gmail.com] > Sent: Sunday, November 29, 2015 2:21 AM > To: qemu-devel@nongnu.org; jcd@tribudubois.net > Cc: Sai Pavan Boddu; qemu-block@nongnu.org; Peter Crosthwaite > Subject: [PATCH v1 1/2] sd: sdhci: Delete over-zealous power check > > This check was conditionalising SD card operation on the card being > powered by the SDHCI host controller. It is however possible > (particularly in embedded systems) for the power control of the SD card > to be managed outside of SDHCI. This can be as trivial as hard-wiring > the SD slot VCC to a constant power-rail. > > This means the guest SDHCI can validly opt-out of the SDHCI power > control feature while still using the card. So delete this check to > allow operation of the card with SDHCI power control. > > This is needed for at least Xilinx Zynq and also makes Freescale i.MX25 > work for me. The digilent Zybo board has a public schematic > which shows SD VCC hardwiring: > > http://digilentinc.com/Data/Products/ZYBO/ZYBO_sch_VB.3.pdf > bottom of page 3. > > Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> Patch is good with the change. Reviewed-by: Sai Pavan Boddu <saipava@xilinx.com> Thanks, Sai Pavan > --- > > hw/sd/sdhci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c > index d70d1a6..ed536ee 100644 > --- a/hw/sd/sdhci.c > +++ b/hw/sd/sdhci.c > @@ -831,7 +831,7 @@ static void sdhci_data_transfer(void *opaque) > > static bool sdhci_can_issue_command(SDHCIState *s) > { > - if (!SDHC_CLOCK_IS_ON(s->clkcon) || !(s->pwrcon & SDHC_POWER_ON) || > + if (!SDHC_CLOCK_IS_ON(s->clkcon) || > (((s->prnsts & SDHC_DATA_INHIBIT) || s->stopped_state) && > ((s->cmdreg & SDHC_CMD_DATA_PRESENT) || > ((s->cmdreg & SDHC_CMD_RESPONSE) == SDHC_CMD_RSP_WITH_BUSY && > -- > 1.9.1
CCing Andrew who ran into a similar issue for rPI. On Sat, Nov 28, 2015 at 12:50 PM, Peter Crosthwaite <crosthwaitepeter@gmail.com> wrote: > This check was conditionalising SD card operation on the card being > powered by the SDHCI host controller. It is however possible > (particularly in embedded systems) for the power control of the SD card > to be managed outside of SDHCI. This can be as trivial as hard-wiring > the SD slot VCC to a constant power-rail. > > This means the guest SDHCI can validly opt-out of the SDHCI power > control feature while still using the card. So delete this check to > allow operation of the card with SDHCI power control. > > This is needed for at least Xilinx Zynq and also makes Freescale i.MX25 > work for me. The digilent Zybo board has a public schematic > which shows SD VCC hardwiring: > > http://digilentinc.com/Data/Products/ZYBO/ZYBO_sch_VB.3.pdf > bottom of page 3. > > Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> > --- > > hw/sd/sdhci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c > index d70d1a6..ed536ee 100644 > --- a/hw/sd/sdhci.c > +++ b/hw/sd/sdhci.c > @@ -831,7 +831,7 @@ static void sdhci_data_transfer(void *opaque) > > static bool sdhci_can_issue_command(SDHCIState *s) > { > - if (!SDHC_CLOCK_IS_ON(s->clkcon) || !(s->pwrcon & SDHC_POWER_ON) || > + if (!SDHC_CLOCK_IS_ON(s->clkcon) || > (((s->prnsts & SDHC_DATA_INHIBIT) || s->stopped_state) && > ((s->cmdreg & SDHC_CMD_DATA_PRESENT) || > ((s->cmdreg & SDHC_CMD_RESPONSE) == SDHC_CMD_RSP_WITH_BUSY && > -- > 1.9.1 >
Raspberry Pi needs this change as well. I don't mind if it's as implemented below, or conditional under a flag property. Tested-By: Andrew Baumann <Andrew.Baumann@microsoft.com> Thanks, Andrew > From: Peter Crosthwaite [mailto:crosthwaitepeter@gmail.com] > Sent: Thursday, 10 December 2015 12:55 > > CCing Andrew who ran into a similar issue for rPI. > > On Sat, Nov 28, 2015 at 12:50 PM, Peter Crosthwaite > <crosthwaitepeter@gmail.com> wrote: > > This check was conditionalising SD card operation on the card being > > powered by the SDHCI host controller. It is however possible > > (particularly in embedded systems) for the power control of the SD card > > to be managed outside of SDHCI. This can be as trivial as hard-wiring > > the SD slot VCC to a constant power-rail. > > > > This means the guest SDHCI can validly opt-out of the SDHCI power > > control feature while still using the card. So delete this check to > > allow operation of the card with SDHCI power control. > > > > This is needed for at least Xilinx Zynq and also makes Freescale i.MX25 > > work for me. The digilent Zybo board has a public schematic > > which shows SD VCC hardwiring: > > > > http://digilentinc.com/Data/Products/ZYBO/ZYBO_sch_VB.3.pdf > > bottom of page 3. > > > > Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> > > --- > > > > hw/sd/sdhci.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c > > index d70d1a6..ed536ee 100644 > > --- a/hw/sd/sdhci.c > > +++ b/hw/sd/sdhci.c > > @@ -831,7 +831,7 @@ static void sdhci_data_transfer(void *opaque) > > > > static bool sdhci_can_issue_command(SDHCIState *s) > > { > > - if (!SDHC_CLOCK_IS_ON(s->clkcon) || !(s->pwrcon & > SDHC_POWER_ON) || > > + if (!SDHC_CLOCK_IS_ON(s->clkcon) || > > (((s->prnsts & SDHC_DATA_INHIBIT) || s->stopped_state) && > > ((s->cmdreg & SDHC_CMD_DATA_PRESENT) || > > ((s->cmdreg & SDHC_CMD_RESPONSE) == > SDHC_CMD_RSP_WITH_BUSY && > > -- > > 1.9.1 > >
diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c index d70d1a6..ed536ee 100644 --- a/hw/sd/sdhci.c +++ b/hw/sd/sdhci.c @@ -831,7 +831,7 @@ static void sdhci_data_transfer(void *opaque) static bool sdhci_can_issue_command(SDHCIState *s) { - if (!SDHC_CLOCK_IS_ON(s->clkcon) || !(s->pwrcon & SDHC_POWER_ON) || + if (!SDHC_CLOCK_IS_ON(s->clkcon) || (((s->prnsts & SDHC_DATA_INHIBIT) || s->stopped_state) && ((s->cmdreg & SDHC_CMD_DATA_PRESENT) || ((s->cmdreg & SDHC_CMD_RESPONSE) == SDHC_CMD_RSP_WITH_BUSY &&
This check was conditionalising SD card operation on the card being powered by the SDHCI host controller. It is however possible (particularly in embedded systems) for the power control of the SD card to be managed outside of SDHCI. This can be as trivial as hard-wiring the SD slot VCC to a constant power-rail. This means the guest SDHCI can validly opt-out of the SDHCI power control feature while still using the card. So delete this check to allow operation of the card with SDHCI power control. This is needed for at least Xilinx Zynq and also makes Freescale i.MX25 work for me. The digilent Zybo board has a public schematic which shows SD VCC hardwiring: http://digilentinc.com/Data/Products/ZYBO/ZYBO_sch_VB.3.pdf bottom of page 3. Signed-off-by: Peter Crosthwaite <crosthwaite.peter@gmail.com> --- hw/sd/sdhci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)