On Mon, Mar 17, 2008 at 11:36 AM, Stephen Neuendorffer <[EMAIL PROTECTED]> wrote: > It appears that in some cases, the sync word might not be recognized > by the hardware correctly. If this happens, then attempting to read > from the port results in an unrecoverable error because of the design > of the FPGA core. This patch updates the code to check the status of > the device before reading the IDCODE, in order to avoid entering this > unrecoverable state. This patch also adds additional NOOP commands > into the sychronization sequence, which appears to be necessary to > avoid the condition on some hardware. > > Signed-off-by: Stephen Neuendorffer <[EMAIL PROTECTED]> Acked-by: Grant Likely <[EMAIL PROTECTED]>
> --- > drivers/char/xilinx_hwicap/xilinx_hwicap.c | 18 ++++++++++++++++++ > 1 files changed, 18 insertions(+), 0 deletions(-) > > diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c > b/drivers/char/xilinx_hwicap/xilinx_hwicap.c > index 304727d..5b8d646 100644 > --- a/drivers/char/xilinx_hwicap/xilinx_hwicap.c > +++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c > @@ -250,8 +250,26 @@ static int hwicap_get_configuration_register(struct > hwicap_drvdata *drvdata, > * Create the data to be written to the ICAP. > */ > buffer[index++] = XHI_DUMMY_PACKET; > + buffer[index++] = XHI_NOOP_PACKET; > buffer[index++] = XHI_SYNC_PACKET; > buffer[index++] = XHI_NOOP_PACKET; > + buffer[index++] = XHI_NOOP_PACKET; > + > + /* > + * Write the data to the FIFO and initiate the transfer of data > present > + * in the FIFO to the ICAP device. > + */ > + status = drvdata->config->set_configuration(drvdata, > + &buffer[0], index); > + if (status) > + return status; > + > + /* If the syncword was not found, then we need to start over. */ > + status = drvdata->config->get_status(drvdata); > + if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK) > + return -EIO; > + > + index = 0; > buffer[index++] = hwicap_type_1_read(reg) | 1; > buffer[index++] = XHI_NOOP_PACKET; > buffer[index++] = XHI_NOOP_PACKET; > -- > 1.5.3.4-dirty > > > > -- > 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/ > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
