Re: [PATCH] ACPI: EC: restart failed command

[Len Brown <lenb@kernel.org>]

refreshed previous version of this patch with this one.

thanks,
-len

On Wed, 12 Nov 2008, Alexey Starikovskiy wrote:

> Restart current transaction if we recieved unexpected GPEs instead
> of needed ones.
> 
> Referencies: http://bugzilla.kernel.org/show_bug.cgi?id=11896
> Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
> ---
> 
>  drivers/acpi/ec.c |   41 +++++++++++++++++++++++++++++------------
>  1 files changed, 29 insertions(+), 12 deletions(-)
> 
> 
> diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
> index db7d67e..87337b0 100644
> --- a/drivers/acpi/ec.c
> +++ b/drivers/acpi/ec.c
> @@ -100,6 +100,8 @@ struct transaction {
>  	u8 *rdata;
>  	unsigned short irq_count;
>  	u8 command;
> +	u8 wi;
> +	u8 ri;
>  	u8 wlen;
>  	u8 rlen;
>  	bool done;
> @@ -185,26 +187,34 @@ static int ec_transaction_done(struct acpi_ec *ec)
>  	return ret;
>  }
>  
> +static void start_transaction(struct acpi_ec *ec)
> +{
> +	ec->curr->irq_count = ec->curr->wi = ec->curr->ri = 0;
> +	ec->curr->done = false;
> +	acpi_ec_write_cmd(ec, ec->curr->command);
> +}
> +
>  static void gpe_transaction(struct acpi_ec *ec, u8 status)
>  {
>  	unsigned long flags;
>  	spin_lock_irqsave(&ec->curr_lock, flags);
>  	if (!ec->curr)
>  		goto unlock;
> -	if (ec->curr->wlen > 0) {
> -		if ((status & ACPI_EC_FLAG_IBF) == 0) {
> -			acpi_ec_write_data(ec, *(ec->curr->wdata++));
> -			--ec->curr->wlen;
> -		} else
> +	if (ec->curr->wlen > ec->curr->wi) {
> +		if ((status & ACPI_EC_FLAG_IBF) == 0)
> +			acpi_ec_write_data(ec,
> +				ec->curr->wdata[ec->curr->wi++]);
> +		else
>  			goto err;
> -	} else if (ec->curr->rlen > 0) {
> +	} else if (ec->curr->rlen > ec->curr->ri) {
>  		if ((status & ACPI_EC_FLAG_OBF) == 1) {
> -			*(ec->curr->rdata++) = acpi_ec_read_data(ec);
> -			if (--ec->curr->rlen == 0)
> +			ec->curr->rdata[ec->curr->ri++] = acpi_ec_read_data(ec);
> +			if (ec->curr->rlen == ec->curr->ri)
>  				ec->curr->done = true;
>  		} else
>  			goto err;
> -	} else if (ec->curr->wlen == 0 && (status & ACPI_EC_FLAG_IBF) == 0)
> +	} else if (ec->curr->wlen == ec->curr->wi &&
> +		   (status & ACPI_EC_FLAG_IBF) == 0)
>  		ec->curr->done = true;
>  	goto unlock;
>  err:
> @@ -219,6 +229,15 @@ static int acpi_ec_wait(struct acpi_ec *ec)
>  	if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
>  			       msecs_to_jiffies(ACPI_EC_DELAY)))
>  		return 0;
> +	/* try restart command if we get any false interrupts */
> +	if (ec->curr->irq_count &&
> +	    (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
> +		pr_debug(PREFIX "controller reset, restart transaction\n");
> +		start_transaction(ec);
> +		if (wait_event_timeout(ec->wait, ec_transaction_done(ec),
> +					msecs_to_jiffies(ACPI_EC_DELAY)))
> +			return 0;
> +	}
>  	/* missing GPEs, switch back to poll mode */
>  	if (printk_ratelimit())
>  		pr_info(PREFIX "missing confirmations, "
> @@ -268,10 +287,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
>  	/* start transaction */
>  	spin_lock_irqsave(&ec->curr_lock, tmp);
>  	/* following two actions should be kept atomic */
> -	t->irq_count = 0;
> -	t->done = false;
>  	ec->curr = t;
> -	acpi_ec_write_cmd(ec, ec->curr->command);
> +	start_transaction(ec);
>  	if (ec->curr->command == ACPI_EC_COMMAND_QUERY)
>  		clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags);
>  	spin_unlock_irqrestore(&ec->curr_lock, tmp);
>