On 30.04.2020 11:42, Eugen Hristev - M18282 wrote: > On 30.04.2020 11:24, Alexandru Ardelean wrote: >> From: Lars-Peter Clausen <lars@xxxxxxxxxx> >> >> It is clear that we transition to INDIO_DIRECT_MODE when disabling the >> buffer(s) and it is also clear that we transition from INDIO_DIRECT_MODE >> when enabling the buffer(s). So leaving the currentmode field >> INDIO_DIRECT_MODE until after the preenable() callback and updating it to >> INDIO_DIRECT_MODE before the postdisable() callback doesn't add additional >> value. On the other hand some drivers will need to perform different >> actions depending on which mode the device is going to operate in/was >> operating in. >> >> Moving the update of currentmode before preenable() and after postdisable() >> enables us to have drivers which perform mode dependent actions in those >> callbacks. >> >> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> >> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> >> --- >> >> This patch is also a V2 of this older patch from a while ago: >> https://lore.kernel.org/linux-iio/1431525891-19285-5-git-send-email-lars@xxxxxxxxxx/ >> >> However, in this recent context, it comes to fix this: >> https://lore.kernel.org/linux-iio/b9ab676489de3575984dac5610fcf05fd8742a38.camel@xxxxxxxxxx/T/#mc09284c8f79250b92a52fd5b8d1f541d1c02c0c0 >> >> At this point, I don't have a clear idea if this approach is good or >> not; since the motivation is to fix the at91 adc. >> Hence the RFC. >> >> Some excerpt from the AT91 discussion: >> ------------------------------------------------------------------- >> I decided to do a bit of shell magic for this: >> >> get_files() { >> git grep -w iio_buffer_setup_ops | grep drivers | cut -d: -f1 | sort | uniq >> } >> >> for file in $(get_files) ; do >> if grep -q currentmode $file ; then >> echo $file >> fi >> done >> >> It finds 4 drivers. >> Though, `get_files()` will return 56 files. >> >> drivers/iio/accel/bmc150-accel-core.c >> drivers/iio/adc/at91-sama5d2_adc.c >> drivers/iio/adc/stm32-dfsdm-adc.c >> drivers/iio/magnetometer/rm3100-core.c >> >> The rm3100 driver doesn't do any checks in the setup_ops for 'currentmode' as >> far as I could see. >> >> So, Lars' patch could work nicely to fix this current case and not break others. >> >> Semantically though, it would sound nicer to have a 'nextmode' parameter >> somewhere; maybe on the setup_ops(indio_dev, nextmode)? >> Though, only those 3 drivers would really ever use it; so doing it like that >> sounds like overkill. >> >> So, we're left with Lars' patch or we could add an 'indio_dev->nextmode' field, >> that may be used in just these 3 drivers [which again: sounds overkill at this >> point in time]. >> >> Alternatively, this 'indio_dev->currentmode' could be removed from all these 3 >> drivers somehow. But that needs testing and a thorough understanding of all 3 >> drivers and what they're doing, to do properly. >> ------------------------------------------------------------------- > > Hi Alex, > > Thanks for finding this. I will test this with the at91-sama5d2_adc > driver on Jonathan's testing branch. I will let you know of the results. > > Eugen Hi, For sama5d2-xplained, hw trigger testing, at91-sama5d2_adc driver, Tested-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> I did not get my hands on the touchscreen yet, but hopefully soon. Thanks again, Eugen > >> >> drivers/iio/industrialio-buffer.c | 8 +++----- >> 1 file changed, 3 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c >> index 30af8af8f312..efcc44b62946 100644 >> --- a/drivers/iio/industrialio-buffer.c >> +++ b/drivers/iio/industrialio-buffer.c >> @@ -989,6 +989,7 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, >> indio_dev->active_scan_mask = config->scan_mask; >> indio_dev->scan_timestamp = config->scan_timestamp; >> indio_dev->scan_bytes = config->scan_bytes; >> + indio_dev->currentmode = config->mode; >> >> iio_update_demux(indio_dev); >> >> @@ -1024,8 +1025,6 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, >> goto err_disable_buffers; >> } >> >> - indio_dev->currentmode = config->mode; >> - >> if (indio_dev->setup_ops->postenable) { >> ret = indio_dev->setup_ops->postenable(indio_dev); >> if (ret) { >> @@ -1042,10 +1041,10 @@ static int iio_enable_buffers(struct iio_dev *indio_dev, >> buffer_list) >> iio_buffer_disable(buffer, indio_dev); >> err_run_postdisable: >> - indio_dev->currentmode = INDIO_DIRECT_MODE; >> if (indio_dev->setup_ops->postdisable) >> indio_dev->setup_ops->postdisable(indio_dev); >> err_undo_config: >> + indio_dev->currentmode = INDIO_DIRECT_MODE; >> indio_dev->active_scan_mask = NULL; >> >> return ret; >> @@ -1080,8 +1079,6 @@ static int iio_disable_buffers(struct iio_dev *indio_dev) >> ret = ret2; >> } >> >> - indio_dev->currentmode = INDIO_DIRECT_MODE; >> - >> if (indio_dev->setup_ops->postdisable) { >> ret2 = indio_dev->setup_ops->postdisable(indio_dev); >> if (ret2 && !ret) >> @@ -1090,6 +1087,7 @@ static int iio_disable_buffers(struct iio_dev *indio_dev) >> >> iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask); >> indio_dev->active_scan_mask = NULL; >> + indio_dev->currentmode = INDIO_DIRECT_MODE; >> >> return ret; >> } >> -- >> 2.17.1 >> >
