From 23e0618ca0255d12798acd3ae37fd98d0def7070 Mon Sep 17 00:00:00 2001 From: Christian Eggers Date: Wed, 9 Sep 2020 17:44:39 +0200 Subject: iio: light: as73211: Increase measurement timeout We found some sensors which are much slower (20% at room temperature) than nominal. According to the data sheet, up to 27% is possible. Now I add 33% to the nominal time out, hopefully this is enough. Signed-off-by: Christian Eggers Link: https://lore.kernel.org/r/20200909154439.10308-1-ceggers@arri.de Fixes: 403e5586b52e ("iio: light: as73211: New driver") Signed-off-by: Jonathan Cameron --- drivers/iio/light/as73211.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/iio/light') diff --git a/drivers/iio/light/as73211.c b/drivers/iio/light/as73211.c index b1178dfc1f65..7b32dfaee9b3 100644 --- a/drivers/iio/light/as73211.c +++ b/drivers/iio/light/as73211.c @@ -259,10 +259,9 @@ static int as73211_req_data(struct as73211_data *data) data->osr &= ~AS73211_OSR_SS; /* - * Add some extra margin for the timeout. sensor timing is not as precise - * as our one ... + * Add 33% extra margin for the timeout. fclk,min = fclk,typ - 27%. */ - time_us += time_us / 8; + time_us += time_us / 3; if (data->client->irq) { ret = wait_for_completion_timeout(&data->completion, usecs_to_jiffies(time_us)); if (!ret) { -- cgit v1.2.3 From 0456ecf34d466261970e0ff92b2b9c78a4908637 Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Wed, 22 Jul 2020 16:50:44 +0100 Subject: iio:light:si1145: Fix timestamp alignment and prevent data leak. One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses a 24 byte array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable array in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc so no data can leak appart from previous readings. Depending on the enabled channels, the location of the timestamp can be at various aligned offsets through the buffer. As such we any use of a structure to enforce this alignment would incorrectly suggest a single location for the timestamp. Comments adjusted to express this clearly in the code. Fixes: ac45e57f1590 ("iio: light: Add driver for Silabs si1132, si1141/2/3 and si1145/6/7 ambient light, uv index and proximity sensors") Reported-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Cc: Peter Meerwald-Stadler Cc: Link: https://lore.kernel.org/r/20200722155103.979802-9-jic23@kernel.org --- drivers/iio/light/si1145.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'drivers/iio/light') diff --git a/drivers/iio/light/si1145.c b/drivers/iio/light/si1145.c index 155faaea8c72..087ef953041d 100644 --- a/drivers/iio/light/si1145.c +++ b/drivers/iio/light/si1145.c @@ -168,6 +168,7 @@ struct si1145_part_info { * @part_info: Part information * @trig: Pointer to iio trigger * @meas_rate: Value of MEAS_RATE register. Only set in HW in auto mode + * @buffer: Used to pack data read from sensor. */ struct si1145_data { struct i2c_client *client; @@ -179,6 +180,14 @@ struct si1145_data { bool autonomous; struct iio_trigger *trig; int meas_rate; + /* + * Ensure timestamp will be naturally aligned if present. + * Maximum buffer size (may be only partly used if not all + * channels are enabled): + * 6*2 bytes channels data + 4 bytes alignment + + * 8 bytes timestamp + */ + u8 buffer[24] __aligned(8); }; /* @@ -440,12 +449,6 @@ static irqreturn_t si1145_trigger_handler(int irq, void *private) struct iio_poll_func *pf = private; struct iio_dev *indio_dev = pf->indio_dev; struct si1145_data *data = iio_priv(indio_dev); - /* - * Maximum buffer size: - * 6*2 bytes channels data + 4 bytes alignment + - * 8 bytes timestamp - */ - u8 buffer[24]; int i, j = 0; int ret; u8 irq_status = 0; @@ -478,7 +481,7 @@ static irqreturn_t si1145_trigger_handler(int irq, void *private) ret = i2c_smbus_read_i2c_block_data_or_emulated( data->client, indio_dev->channels[i].address, - sizeof(u16) * run, &buffer[j]); + sizeof(u16) * run, &data->buffer[j]); if (ret < 0) goto done; j += run * sizeof(u16); @@ -493,7 +496,7 @@ static irqreturn_t si1145_trigger_handler(int irq, void *private) goto done; } - iio_push_to_buffers_with_timestamp(indio_dev, buffer, + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, iio_get_time_ns(indio_dev)); done: -- cgit v1.2.3