2024-06-04 21:28:35

by Wolfram Sang

Subject: [PATCH 1/1] usb: typec: tcpm: use 'time_left' variable with wait_for_completion_timeout()

There is a confusing pattern in the kernel to use a variable named 'timeout' to
store the result of wait_for_completion_timeout() causing patterns like:

timeout = wait_for_completion_timeout(...)
if (!timeout) return -ETIMEDOUT;

with all kinds of permutations. Use 'time_left' as a variable to make the code
self explaining.

Signed-off-by: Wolfram Sang <[email protected]>
---
drivers/usb/typec/tcpm/tcpm.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 8a1af08f71b6..e46148c19be3 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -943,7 +943,7 @@ static int tcpm_pd_transmit(struct tcpm_port *port,
enum tcpm_transmit_type tx_sop_type,
const struct pd_message *msg)
{
- unsigned long timeout;
+ unsigned long time_left;
int ret;
unsigned int negotiated_rev;

@@ -968,10 +968,10 @@ static int tcpm_pd_transmit(struct tcpm_port *port,
return ret;

mutex_unlock(&port->lock);
- timeout = wait_for_completion_timeout(&port->tx_complete,
- msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
+ time_left = wait_for_completion_timeout(&port->tx_complete,
+ msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
mutex_lock(&port->lock);
- if (!timeout)
+ if (!time_left)
return -ETIMEDOUT;

switch (port->tx_status) {
--
2.43.0

2024-06-06 12:08:07

by Heikki Krogerus

Subject: Re: [PATCH 1/1] usb: typec: tcpm: use 'time_left' variable with wait_for_completion_timeout()

On Tue, Jun 04, 2024 at 11:27:31PM +0200, Wolfram Sang wrote:
> There is a confusing pattern in the kernel to use a variable named 'timeout' to
> store the result of wait_for_completion_timeout() causing patterns like:
>
> timeout = wait_for_completion_timeout(...)
> if (!timeout) return -ETIMEDOUT;
>
> with all kinds of permutations. Use 'time_left' as a variable to make the code
> self explaining.
>
> Signed-off-by: Wolfram Sang <[email protected]>

Reviewed-by: Heikki Krogerus <[email protected]>

> ---
> drivers/usb/typec/tcpm/tcpm.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 8a1af08f71b6..e46148c19be3 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -943,7 +943,7 @@ static int tcpm_pd_transmit(struct tcpm_port *port,
> enum tcpm_transmit_type tx_sop_type,
> const struct pd_message *msg)
> {
> - unsigned long timeout;
> + unsigned long time_left;
> int ret;
> unsigned int negotiated_rev;
>
> @@ -968,10 +968,10 @@ static int tcpm_pd_transmit(struct tcpm_port *port,
> return ret;
>
> mutex_unlock(&port->lock);
> - timeout = wait_for_completion_timeout(&port->tx_complete,
> - msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
> + time_left = wait_for_completion_timeout(&port->tx_complete,
> + msecs_to_jiffies(PD_T_TCPC_TX_TIMEOUT));
> mutex_lock(&port->lock);
> - if (!timeout)
> + if (!time_left)
> return -ETIMEDOUT;
>
> switch (port->tx_status) {
> --
> 2.43.0

--
heikki