Re: [PATCH v7 1/4] Input: stmfts - wait for controller ready after reset
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2026-09-25 19:27:42
Also in:
linux-arm-msm, linux-devicetree, linux-input, lkml, phone-devel, stable
Hi David, On Mon, Sep 07, 2026 at 12:50:19PM +0200, David Heidelberg via B4 Relay wrote:
quoted hunk ↗ jump to hunk
-static void stmfts_reset(struct stmfts_data *sdata) +static int stmfts_reset(struct stmfts_data *sdata) { gpiod_set_value_cansleep(sdata->reset_gpio, 1); msleep(20); + reinit_completion(&sdata->cmd_done); gpiod_set_value_cansleep(sdata->reset_gpio, 0); - msleep(50); + enable_irq(sdata->client->irq); + + if (!wait_for_completion_timeout(&sdata->cmd_done, + msecs_to_jiffies(STMFTS_RESET_TIMEOUT_MS))) + return -ETIMEDOUT; + + return 0; } static int stmfts_configure(struct stmfts_data *sdata) { int err; err = stmfts_command(sdata, STMFTS_SYSTEM_RESET); if (err)@@ -593,42 +602,47 @@ static int stmfts_power_on(struct stmfts_data *sdata) return err; /* * The datasheet does not specify the power on time, but considering * that the reset time is < 10ms, I sleep 20ms to be sure */ msleep(20); - if (sdata->reset_gpio) - stmfts_reset(sdata); + if (sdata->reset_gpio) { + err = stmfts_reset(sdata); + if (err) { + dev_err(&sdata->client->dev, + "controller not ready after reset: %d\n", err); + goto err_disable_irq; + } + } else { + enable_irq(sdata->client->irq); + msleep(50); + } err = stmfts_read_system_info(sdata); if (err) - goto err_disable_regulators; - - enable_irq(sdata->client->irq); - - msleep(50); + goto err_disable_irq;
I think the logic is becoming quite convoluted here, and factored out
stmfts_reset() does not help. How about we make it look like this:
static int stmfts_power_on(struct stmfts_data *sdata)
{
int err;
if (sdata->reset_gpio) {
gpiod_set_value_cansleep(sdata->reset_gpio, 1);
/* a short delay before powering up */
usleep_range(1000, 1500);
}
err = regulator_bulk_enable(ARRAY_SIZE(stmfts_supplies),
sdata->supplies);
if (err)
return err;
if (sdata->reset_gpio) {
reinit_completion(&sdata->cmd_done);
/*
* The datasheet does not specify the power on time, but
* considering that the reset time is < 10ms, sleep for 20ms
* to be sure before releasing reset line.
*/
msleep(20);
gpiod_set_value_cansleep(sdata->reset_gpio, 0);
enable_irq(sdata->client->irq);
if (!wait_for_completion_timeout(&sdata->cmd_done,
msecs_to_jiffies(STMFTS_RESET_TIMEOUT_MS))) {
dev_err(&sdata->client->dev, "controller not ready after reset");
err = -ETIMEDOUT;
goto err_disable_irq;
}
} else {
/*
* We do not know the real controller state (was it powered
* off or reset). Let's hope that this is enough time to
* initialize.
*/
msleep(70);
enable_irq(sdata->client->irq);
}
err = sdata->ops->configure(sdata);
if (err)
goto err_disable_irq;
/*
* At this point no one is using the touchscreen
* and I don't really care about the return value
*/
(void)i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
return 0;
err_disable_irq:
disable_irq(sdata->client->irq);
regulator_bulk_disable(ARRAY_SIZE(stmfts_supplies), sdata->supplies);
return err;
}
Thanks.
--
Dmitry