Re: [PATCH v2] Input: iqs269a - Use scope-based resource management in iqs269_parse_chan()

Jeff LaBundy
2024-03-04T17:10:55Z

Hi Markus,

On Mon, Mar 04, 2024 at 10:55:11AM +0100, Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Mon, 4 Mar 2024 10:30:52 +0100
>
> Scope-based resource management became supported also for this software
> area by contributions of Jonathan Cameron on 2024-02-17.
>
> device property: Add cleanup.h based fwnode_handle_put() scope based cleanup.
> https://lore.kernel.org/r/20240217164249.921878-3-jic23@kernel.org
>
>
> * Thus use the attribute “__free(fwnode_handle)”.
>
> * Reduce the scope for the local variable “ev_node” into a for loop.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>
> v2:
> An other cleanup technique was applied as requested by Dmitry Torokhov.
>
>
> drivers/input/misc/iqs269a.c | 73 ++++++++++++++++++------------------
> 1 file changed, 37 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
> index cd14ff9f57cf..9caee936927b 100644
> --- a/drivers/input/misc/iqs269a.c
> +++ b/drivers/input/misc/iqs269a.c
> @@ -557,7 +557,6 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
> const struct fwnode_handle *ch_node)
> {
> struct i2c_client *client = iqs269->client;
> - struct fwnode_handle *ev_node;
> struct iqs269_ch_reg *ch_reg;
> u16 engine_a, engine_b;
> unsigned int reg, val;
> @@ -734,47 +733,49 @@ static int iqs269_parse_chan(struct iqs269_private *iqs269,
> }
>
> for (i = 0; i < ARRAY_SIZE(iqs269_events); i++) {
> - ev_node = fwnode_get_named_child_node(ch_node,
> - iqs269_events[i].name);
> - if (!ev_node)
> - continue;
> -
> - if (!fwnode_property_read_u32(ev_node, "azoteq,thresh", &val)) {
> - if (val > IQS269_CHx_THRESH_MAX) {
> - dev_err(&client->dev,
> - "Invalid channel %u threshold: %u\n",
> - reg, val);
> - fwnode_handle_put(ev_node);
> - return -EINVAL;
> + {
> + struct fwnode_handle *ev_node __free(fwnode_handle)
> + = fwnode_get_named_child_node(ch_node,
> + iqs269_events[i].name);
> +
> + if (!ev_node)
> + continue;
> +
> + if (!fwnode_property_read_u32(ev_node, "azoteq,thresh", &val)) {
> + if (val > IQS269_CHx_THRESH_MAX) {
> + dev_err(&client->dev,
> + "Invalid channel %u threshold: %u\n",
> + reg, val);
> + return -EINVAL;
> + }
> +
> + ch_reg->thresh[iqs269_events[i].th_offs] = val;

I may just be a curmudgeon, but this is another NAK for me. The dummy
curly braces and extra indentation make the code difficult to understand,
and this simply does not seem like a natural way to write a driver. Just
to remove 2-3 calls to fwnode_handle_put()?

> }
>
> - ch_reg->thresh[iqs269_events[i].th_offs] = val;
> - }
> -
> - if (!fwnode_property_read_u32(ev_node, "azoteq,hyst", &val)) {
> - u8 *hyst = &ch_reg->hyst;
> -
> - if (val > IQS269_CHx_HYST_MAX) {
> - dev_err(&client->dev,
> - "Invalid channel %u hysteresis: %u\n",
> - reg, val);
> - fwnode_handle_put(ev_node);
> - return -EINVAL;
> + if (!fwnode_property_read_u32(ev_node, "azoteq,hyst", &val)) {
> + u8 *hyst = &ch_reg->hyst;
> +
> + if (val > IQS269_CHx_HYST_MAX) {
> + dev_err(&client->dev,
> + "Invalid channel %u hysteresis: %u\n",
> + reg, val);
> + return -EINVAL;
> + }
> +
> + if (i == IQS269_EVENT_DEEP_DN ||
> + i == IQS269_EVENT_DEEP_UP) {
> + *hyst &= ~IQS269_CHx_HYST_DEEP_MASK;
> + *hyst |= (val << IQS269_CHx_HYST_DEEP_SHIFT);
> + } else if (i == IQS269_EVENT_TOUCH_DN ||
> + i == IQS269_EVENT_TOUCH_UP) {
> + *hyst &= ~IQS269_CHx_HYST_TOUCH_MASK;
> + *hyst |= val;
> + }
> }
>
> - if (i == IQS269_EVENT_DEEP_DN ||
> - i == IQS269_EVENT_DEEP_UP) {
> - *hyst &= ~IQS269_CHx_HYST_DEEP_MASK;
> - *hyst |= (val << IQS269_CHx_HYST_DEEP_SHIFT);
> - } else if (i == IQS269_EVENT_TOUCH_DN ||
> - i == IQS269_EVENT_TOUCH_UP) {
> - *hyst &= ~IQS269_CHx_HYST_TOUCH_MASK;
> - *hyst |= val;
> - }
> + error = fwnode_property_read_u32(ev_node, "linux,code", &val);
> }
>
> - error = fwnode_property_read_u32(ev_node, "linux,code", &val);
> - fwnode_handle_put(ev_node);
> if (error == -EINVAL) {
> continue;
> } else if (error) {
> --
> 2.44.0
>

Kind regards,
Jeff LaBundy