Messages in this thread | | | Subject | Re: [PATCH] mfd: vexpress: Handle pending config transactions | From | "Jon Medhurst (Tixy)" <> | Date | Thu, 25 Apr 2013 14:02:45 +0100 |
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On Wed, 2013-04-24 at 17:31 +0100, Pawel Moll wrote: > The config transactions "scheduler" was hopelessly broken, > repeating completed transaction instead of picking up > next pending one. > > Fixed now. Also improved debug messages. > > Signed-off-by: Pawel Moll <pawel.moll@arm.com> > --- > drivers/mfd/vexpress-config.c | 31 ++++++++++++++++++++----------- > 1 file changed, 20 insertions(+), 11 deletions(-) > > diff --git a/drivers/mfd/vexpress-config.c b/drivers/mfd/vexpress-config.c > index 3c1723aa..4991db3 100644 > --- a/drivers/mfd/vexpress-config.c > +++ b/drivers/mfd/vexpress-config.c > @@ -184,13 +184,14 @@ static int vexpress_config_schedule(struct vexpress_config_trans *trans) > > spin_lock_irqsave(&bridge->transactions_lock, flags); > > - vexpress_config_dump_trans("Executing", trans); > - > - if (list_empty(&bridge->transactions)) > + if (list_empty(&bridge->transactions)) { > + vexpress_config_dump_trans("Executing", trans); > status = bridge->info->func_exec(trans->func->func, > trans->offset, trans->write, trans->data); > - else > + } else { > + vexpress_config_dump_trans("Queuing", trans); > status = VEXPRESS_CONFIG_STATUS_WAIT; > + } > > switch (status) { > case VEXPRESS_CONFIG_STATUS_DONE: > @@ -217,20 +218,28 @@ void vexpress_config_complete(struct vexpress_config_bridge *bridge, > > trans = list_first_entry(&bridge->transactions, > struct vexpress_config_trans, list); > + trans->status = status; > vexpress_config_dump_trans("Completed", trans); > > - trans->status = status; > list_del(&trans->list); > > - if (!list_empty(&bridge->transactions)) { > - vexpress_config_dump_trans("Pending", trans); > + complete(&trans->completion); > + > + while (!list_empty(&bridge->transactions)) { > + trans = list_first_entry(&bridge->transactions, > + struct vexpress_config_trans, list); > > - bridge->info->func_exec(trans->func->func, trans->offset, > - trans->write, trans->data); > + vexpress_config_dump_trans("Executing pending", trans); > + status = bridge->info->func_exec(trans->func->func, > + trans->offset, trans->write, trans->data); > + > + if (status == VEXPRESS_CONFIG_STATUS_DONE) > + vexpress_config_dump_trans("Finished pending", trans); > + else > + break;
For each transaction we execute in this loop, don't we also need to do the actions vexpress_config_complete does? E.g.
trans->status = status; list_del(&trans->list); complete(&trans->completion);
except in the case status==VEXPRESS_CONFIG_STATUS_WAIT.
Or, does the call to func_exec cause vexpress_config_complete() to be called later? (It hadn't better be called synchronously or we get a deadlock).
Actually, if it is called later, there is still a problem because if the call to func_exec returns VEXPRESS_CONFIG_STATUS_DONE then the transaction is left on the list and the while loop will try and execute it again.
> } > - spin_unlock_irqrestore(&bridge->transactions_lock, flags); > > - complete(&trans->completion); > + spin_unlock_irqrestore(&bridge->transactions_lock, flags); > } > EXPORT_SYMBOL(vexpress_config_complete); >
-- Tixy
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