Re: [PATCH 09/16 v2] Input: atmel_mxt_ts - optimize writing ofobject table entries

From: Henrik Rydberg
Date: Fri Apr 13 2012 - 05:10:55 EST


Hi Daniel,

> Write each object using a single bulk i2c write transfer.
>
> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> Reviewed-by: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 28 ++++++++++++++--------------
> 1 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index a865967..3abc5b0 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -628,33 +628,33 @@ end:
> static int mxt_check_reg_init(struct mxt_data *data)
> {
> const struct mxt_platform_data *pdata = data->pdata;
> - struct mxt_object *object;
> struct device *dev = &data->client->dev;
> - int index = 0;
> - int i, j, config_offset, config_size;
> + int i, offset;
> + int ret;
>
> if (!pdata->config) {
> dev_dbg(dev, "No cfg data defined, skipping reg init\n");
> return 0;
> }
>
> - for (i = 0; i < data->info.object_num; i++) {
> - object = data->object_table + i;
> + for (offset = 0, i = 0; i < data->info.object_num; i++) {
> + struct mxt_object *object = &data->object_table[i];
> + size_t config_size;
>
> if (!mxt_object_writable(object->type))
> continue;
>
> config_size = object->size * object->instances;
> - for (j = 0; j < config_size; j++) {
> - config_offset = index + j;
> - if (config_offset > pdata->config_length) {
> - dev_err(dev, "Not enough config data!\n");
> - return -EINVAL;
> - }
> - mxt_write_object(data, object->type, j,
> - pdata->config[config_offset]);
> + if (offset + config_size > pdata->config_length) {
> + dev_err(dev, "Not enough config data!\n");
> + return -EINVAL;
> }
> - index += config_size;
> +
> + ret = mxt_write_reg(data->client, object->start_address,
> + config_size, &pdata->config[offset]);

How big is config_size? Removing the need for a stack copy here would
be better, see patch 11.

> + if (ret)
> + return ret;
> + offset += config_size;
> }
>
> return 0;
> --
> 1.7.7.3
>

Thanks,
Henrik
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