Not really... In this case 'faster' means 'faster ICAP core' not 'faster processor': This is really something that is bounded by the number of cycles.
Steve > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Grant Likely > Sent: Monday, May 05, 2008 1:01 PM > To: Stephen Neuendorffer > Cc: linuxppc-dev@ozlabs.org > Subject: Re: [PATCH] Xilinx: hwicap: cleanup polling timeout. > > On Mon, May 5, 2008 at 12:20 PM, Stephen Neuendorffer > <[EMAIL PROTECTED]> wrote: > > In order to avoid polling forever if an error occurs, this driver > > includes a timeout counter. However, in fast systems, this counter > > wasn't high enough. This patch fixes the bug and also makes the > > buffer-based and fifo-based drivers return the same error condition on > > a timeout (-EIO). > > Would it be better to base the timeout on real time instead of a hard > iteration count? > > Cheers, > g. > > > > > Signed-off-by: Stephen Neuendorffer <[EMAIL PROTECTED]> > > --- > > drivers/char/xilinx_hwicap/buffer_icap.c | 10 ++++++++-- > > drivers/char/xilinx_hwicap/fifo_icap.c | 9 +++++++++ > > drivers/char/xilinx_hwicap/xilinx_hwicap.h | 3 --- > > 3 files changed, 17 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/char/xilinx_hwicap/buffer_icap.c b/drivers/char/xilinx_hwicap/buffer_icap.c > > index aa7f796..0993883 100644 > > --- a/drivers/char/xilinx_hwicap/buffer_icap.c > > +++ b/drivers/char/xilinx_hwicap/buffer_icap.c > > @@ -35,6 +35,12 @@ > > > > #include "buffer_icap.h" > > > > +/* Number of times to poll the done register. This has to be large > > + enough to allow an entire configuration to complete. If an entire > > + page (4kb) is configured at once, that could take up to 4k cycles > > + with a byte-wide icap interface. */ > > +#define XHI_MAX_RETRIES 5000 > > + > > /* Indicates how many bytes will fit in a buffer. (1 BRAM) */ > > #define XHI_MAX_BUFFER_BYTES 2048 > > #define XHI_MAX_BUFFER_INTS (XHI_MAX_BUFFER_BYTES >> 2) > > @@ -208,7 +214,7 @@ static int buffer_icap_device_read(struct hwicap_drvdata *drvdata, > > while (buffer_icap_busy(base_address)) { > > retries++; > > if (retries > XHI_MAX_RETRIES) > > - return -EBUSY; > > + return -EIO; > > } > > return 0; > > > > @@ -242,7 +248,7 @@ static int buffer_icap_device_write(struct hwicap_drvdata *drvdata, > > while (buffer_icap_busy(base_address)) { > > retries++; > > if (retries > XHI_MAX_RETRIES) > > - return -EBUSY; > > + return -EIO; > > } > > return 0; > > > > diff --git a/drivers/char/xilinx_hwicap/fifo_icap.c b/drivers/char/xilinx_hwicap/fifo_icap.c > > index 776b505..d1cd928 100644 > > --- a/drivers/char/xilinx_hwicap/fifo_icap.c > > +++ b/drivers/char/xilinx_hwicap/fifo_icap.c > > @@ -35,6 +35,15 @@ > > > > #include "fifo_icap.h" > > > > +/* Number of times to poll the done register. This has to be large > > + * enough to allow an entire configuration to complete. If an entire > > + * page (4kb) is configured at once, that could take up to 4k cycles > > + * with a byte-wide icap interface. In most cases, this driver is > > + * used with a much smaller fifo, but this should be sufficient in the > > + * worst case. > > + */ > > +#define XHI_MAX_RETRIES 5000 > > + > > /* Register offsets for the XHwIcap device. */ > > #define XHI_GIER_OFFSET 0x1C /* Device Global Interrupt Enable Reg */ > > #define XHI_IPISR_OFFSET 0x20 /* Interrupt Status Register */ > > diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.h > b/drivers/char/xilinx_hwicap/xilinx_hwicap.h > > index 1f9c8b0..fd4be31 100644 > > --- a/drivers/char/xilinx_hwicap/xilinx_hwicap.h > > +++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.h > > @@ -89,9 +89,6 @@ struct hwicap_driver_config { > > void (*reset)(struct hwicap_drvdata *drvdata); > > }; > > > > -/* Number of times to poll the done regsiter */ > > -#define XHI_MAX_RETRIES 10 > > - > > /************ Constant Definitions *************/ > > > > #define XHI_PAD_FRAMES 0x1 > > -- > > 1.5.3.4-dirty > > > > > > > > > > > > -- > 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
