On giovedì 14 aprile 2022 00:55:31 CEST Fabio M. De Francesco wrote: > The use of kmap() is being deprecated in favor of kmap_local_page() > where it is feasible. The same is true for kmap_atomic(). > > In file pci/hmm/hmm.c, function hmm_store() test if we are in atomic > context and, if so, it calls kmap_atomic(), if not, it calls kmap(). > > First of all, in_atomic() shouldn't be used in drivers. This macro > cannot always detect atomic context; in particular, it cannot know > about held spinlocks in non-preemptible kernels. > > Notwithstanding what it is said above, this code doesn't need to care > whether or not it is executing in atomic context. It can simply use > kmap_local_page() / kunmap_local() that can instead do the mapping / > unmapping regardless of the context. > > With kmap_local_page(), the mapping is per thread, CPU local and not > globally visible. Therefore, hmm_store()() is a function where the use > of kmap_local_page() in place of both kmap() and kmap_atomic() is > correctly suited. > > Convert the calls of kmap() / kunmap() and kmap_atomic() / > kunmap_atomic() to kmap_local_page() / kunmap_local() and drop the > unnecessary tests which test if the code is in atomic context. > > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx> > --- > drivers/staging/media/atomisp/pci/hmm/hmm.c | 14 ++------------ > 1 file changed, 2 insertions(+), 12 deletions(-) Hi Mauro, I'm writing for just a gentle ping for this and two other staging/atomisp/ patches that still seem to be waiting to be applied. In the meantime I would like to remind you that Hans de Goede has successfully tested this patch and the other two on both the front and back cams of a chuwi hi8 tablet. Please let me know if there is anything else that is required to be done in order to accept the three patches. Thanks, Fabio M. De Francesco
