| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Thu, 3 Sep 2020 16:20:04 +0300
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Nishant Malpani <nish.malpani25@...il.com>
Cc: Jonathan Cameron <jic23@...nel.org>,
Rob Herring <robh+dt@...nel.org>,
"Bogdan, Dragos" <dragos.bogdan@...log.com>,
darius.berghe@...log.com,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
linux-iio <linux-iio@...r.kernel.org>,
devicetree <devicetree@...r.kernel.org>
Subject: Re: [PATCH v2 1/3] iio: gyro: adxrs290: Add triggered buffer support
On Thu, Sep 3, 2020 at 4:10 PM Nishant Malpani <nish.malpani25@...il.com> wrote:
>
> Provide a way for continuous data capture by setting up buffer support. The
> data ready signal exposed at the SYNC pin of the ADXRS290 is exploited as
> a hardware interrupt which triggers to fill the buffer.
>
> Triggered buffer setup was tested with both hardware trigger (DATA_RDY) and
> software triggers (sysfs-trig & hrtimer).
...
> +static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
> +{
> + struct adxrs290_state *st = iio_priv(indio_dev);
> + int val, ret;
> +
> + if (st->mode == mode) {
> + ret = 0;
> + goto done;
Unlocking the not locked mutex is not good. Have you followed the
Submitting Patches Checklist? It in particular suggests few debug
options, like LOCKDEP, to be enabled.
> + }
> +
> + mutex_lock(&st->lock);
> +
> + ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
> + if (ret < 0)
> + goto done;
> +
> + val = ret;
> +
> + switch (mode) {
> + case ADXRS290_MODE_STANDBY:
> + val &= ~ADXRS290_MEASUREMENT;
> + break;
> + case ADXRS290_MODE_MEASUREMENT:
> + val |= ADXRS290_MEASUREMENT;
> + break;
> + default:
> + ret = -EINVAL;
> + goto done;
> + }
> +
> + ret = adxrs290_spi_write_reg(st->spi,
> + ADXRS290_REG_POWER_CTL,
> + val);
> + if (ret < 0) {
> + dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
> + goto done;
> + }
> +
> + /* update cached mode */
> + st->mode = mode;
> +
> +done:
Much better to call it out_unlock. It will help eliminate the mistakes
like above.
> + mutex_unlock(&st->lock);
> + return ret;
> +}
...
What about
ret = -EINVAL;
> switch (mask) {
> case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> lpf_idx = adxrs290_find_match(adxrs290_lpf_3db_freq_hz_table,
> ARRAY_SIZE(adxrs290_lpf_3db_freq_hz_table),
> val, val2);
> - if (lpf_idx < 0)
> - return -EINVAL;
> + if (lpf_idx < 0) {
> + ret = -EINVAL;
> + break;
> + }
Simple
break;
and so on?
> +
> /* caching the updated state of the low-pass filter */
> st->lpf_3db_freq_idx = lpf_idx;
> /* retrieving the current state of the high-pass filter */
> hpf_idx = st->hpf_3db_freq_idx;
> - return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
> + ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
> + break;
> +
> case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
> hpf_idx = adxrs290_find_match(adxrs290_hpf_3db_freq_hz_table,
> ARRAY_SIZE(adxrs290_hpf_3db_freq_hz_table),
> val, val2);
> - if (hpf_idx < 0)
> - return -EINVAL;
> + if (hpf_idx < 0) {
> + ret = -EINVAL;
> + break;
> + }
> +
> /* caching the updated state of the high-pass filter */
> st->hpf_3db_freq_idx = hpf_idx;
> /* retrieving the current state of the low-pass filter */
> lpf_idx = st->lpf_3db_freq_idx;
> - return adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
> + ret = adxrs290_set_filter_freq(indio_dev, lpf_idx, hpf_idx);
> + break;
> +
> + default:
> + ret = -EINVAL;
> + break;
> }
>
> - return -EINVAL;
> + iio_device_release_direct_mode(indio_dev);
> + return ret;
> }
...
> +static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
> +{
> + /* exercise a bulk data capture starting from reg DATAX0... */
> + ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
> + sizeof(st->buffer.channels));
> + if (ret < 0)
> + goto done;
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
> + pf->timestamp);
> +
> +done:
out_unlock_notify:
> + mutex_unlock(&st->lock);
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
...
> +static int adxrs290_probe_trigger(struct iio_dev *indio_dev)
> +{
> + struct adxrs290_state *st = iio_priv(indio_dev);
> + int ret;
> + if (!st->spi->irq) {
> + dev_info(&st->spi->dev, "no irq, using polling\n");
> + return 0;
> + }
Wouldn't it be better to have this check outside of the function?
And taking this into account...
> +}
...
> + ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
> + &iio_pollfunc_store_time,
> + &adxrs290_trigger_handler, NULL);
> + if (ret < 0)
> + return dev_err_probe(&spi->dev, ret,
> + "iio triggered buffer setup failed\n");
...do you really have to set up a trigger buffer w/o trigger being probed?
> + ret = adxrs290_probe_trigger(indio_dev);
> + if (ret < 0)
> + return ret;
--
With Best Regards,
Andy Shevchenko
Powered by blists - more mailing lists