Hi Patrice, On Fri, Oct 12, 2018 at 3:51 PM Patrice CHOTARD <patrice.chot...@st.com> wrote: > > Hi Bin > > On 10/11/2018 11:06 AM, Bin Meng wrote: > > Hi Patrice, > > > > On Tue, Oct 9, 2018 at 9:41 PM Patrice Chotard <patrice.chot...@st.com> > > wrote: > >> > >> Add uclass_foreach_dev_probe() which iterates through > >> devices of a given uclass. Devices are probed if necessary > >> and are ready to use. > >> > >> Signed-off-by: Patrice Chotard <patrice.chot...@st.com> > >> Reviewed-by: Simon Glass <s...@chromium.org> > >> --- > >> > >> Changes in v3: None > >> Changes in v2: None > >> > >> include/dm/uclass.h | 16 ++++++++++++++++ > >> 1 file changed, 16 insertions(+) > >> > >> diff --git a/include/dm/uclass.h b/include/dm/uclass.h > >> index 6e7c1cd3e8bc..10ccfdce951e 100644 > >> --- a/include/dm/uclass.h > >> +++ b/include/dm/uclass.h > >> @@ -376,4 +376,20 @@ int uclass_resolve_seq(struct udevice *dev); > >> #define uclass_foreach_dev_safe(pos, next, uc) \ > >> list_for_each_entry_safe(pos, next, &uc->dev_head, uclass_node) > >> > >> +/** > >> + * uclass_foreach_dev_probe() - Helper function to iteration through > >> devices > >> + * of given uclass > >> + * > >> + * This creates a for() loop which works through the available devices in > >> + * a uclass in order from start to end. Devices are probed if necessary, > >> + * and ready for use. > >> + * > >> + * @id: Uclass ID > >> + * @dev: struct udevice * to hold the current device. Set to NULL when > >> there > >> + * are no more devices. > >> + */ > >> +#define uclass_foreach_dev_probe(id, dev) \ > >> + for (uclass_first_device(id, &dev); dev; \ > >> + uclass_next_device(&dev)) > > > > Shouldn't we check the return value of uclass_first_device() and > > uclass_next_device()? > > It's not necessary to check the return value of uclass_first_device(id, > &dev) because in any error case, dev is NULL, which is the loop output > condition. This is only for the first iteration. >
Please see the comment of uclass_first_device(). * @devp: Returns pointer to the first device in that uclass if no error * occurred, or NULL if there is no first device, or an error occurred with * that device. * @return 0 if OK (found or not found), other -ve on error So it can return error with a valid dev. > For the other iteration, dev comes from uclass_next_device(&dev), > similarly to uclass_first_device(), in any error case dev is NULL. > Similar please see the comment of uclass_next_device(). Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
