Re: [PATCHv2] fpga: stratix10-soc: remove the pre-set reconfiguration condition

From: Moritz Fischer
Date: Sun May 31 2020 - 15:49:37 EST


On Fri, May 29, 2020 at 08:15:15AM -0500, Richard Gong wrote:
> Hi Moritz,
>
> Sorry for asking.
>
> When you get chance, can you review my version 2 patch submitted on
> 05/15/20?
>
> Regards,
> Richard
>
> On 5/15/20 9:35 AM, richard.gong@xxxxxxxxxxxxxxx wrote:
> > From: Richard Gong <richard.gong@xxxxxxxxx>
> >
> > The reconfiguration mode is pre-set by driver as the full reconfiguration.
> > As a result, user have to change code and recompile the drivers if he or
> > she wants to perform a partial reconfiguration. Removing the pre-set
> > reconfiguration condition so that user can select full or partial
> > reconfiguration via overlay device tree without recompiling the drivers.

Can you help me understand? See comment below, I'm not sure how this
change changes the behavior.
> >
> > Also add an error message if the configuration request is failure.
> >
> > Signed-off-by: Richard Gong <richard.gong@xxxxxxxxx>
> > ---
> > v2: define and use constant values
> > ---
> > drivers/fpga/stratix10-soc.c | 9 +++++++--
> > 1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/fpga/stratix10-soc.c b/drivers/fpga/stratix10-soc.c
> > index 44b7c56..4d52a80 100644
> > --- a/drivers/fpga/stratix10-soc.c
> > +++ b/drivers/fpga/stratix10-soc.c
> > @@ -14,9 +14,13 @@
> > /*
> > * FPGA programming requires a higher level of privilege (EL3), per the SoC
> > * design.
> > + * SoC firmware supports full and partial reconfiguration.
Consider:
"The SoC firmware supports full and partial reconfiguration."
> > */
> > #define NUM_SVC_BUFS 4
> > #define SVC_BUF_SIZE SZ_512K
> > +#define FULL_RECONFIG_FLAG 0
> > +#define PARTIAL_RECONFIG_FLAG 1
> > +
> > /* Indicates buffer is in use if set */
> > #define SVC_BUF_LOCK 0
> > @@ -182,12 +186,12 @@ static int s10_ops_write_init(struct fpga_manager *mgr,
> > uint i;
> > int ret;
> > - ctype.flags = 0;
> > if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
> > dev_dbg(dev, "Requesting partial reconfiguration.\n");
> > - ctype.flags |= BIT(COMMAND_RECONFIG_FLAG_PARTIAL);
> > + ctype.flags = PARTIAL_RECONFIG_FLAG;
> > } else {
> > dev_dbg(dev, "Requesting full reconfiguration.\n");
> > + ctype.flags = FULL_RECONFIG_FLAG;
> > }
Am I missing something here: Doesn't this do the same as before?

Before:
If info->flags & FPGA_MGR_PARTIAL_RECONFIG -> ctype.flags = 0 |
BIT(COMMAND_RECONFIG_FLAG_PARTIAL) -> 1
and ctype->flags = FULL_RECONFIG -> 0 else.

Now:
If info->flags & FPGA_MGR_PARTIAL_RECONFIG -> ctype.flags = PARTIAL_RECONFIG_FLAG -> 1
ctype->flags = FULL_REECONFIG_FLAG -> 0 else.

Am I missing something here? If I don't set the flag for partial
reconfig I'd end up with full reconfiguration in both cases?
If I do set the flag, I get partial reconfiguration in both cases?

> > reinit_completion(&priv->status_return_completion);
> > @@ -210,6 +214,7 @@ static int s10_ops_write_init(struct fpga_manager *mgr,
> > ret = 0;
> > if (!test_and_clear_bit(SVC_STATUS_OK, &priv->status)) {
> > + dev_err(dev, "RECONFIG_REQUEST failed\n");
> > ret = -ETIMEDOUT;
> > goto init_done;
> > }
> >

Thanks,
Moritz