Hi,
On Thu, Apr 25, 2024 at 8:03 PM Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:
>
> On Thu, Apr 25, 2024 at 10:04:49AM -0700, Doug Anderson wrote:
> > Hi,
> >
> > On Thu, Apr 25, 2024 at 1:19 AM Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
> > >
> > > > @@ -279,6 +281,8 @@ enum mipi_dsi_dcs_tear_mode {
> > > >
> > > > ssize_t mipi_dsi_dcs_write_buffer(struct mipi_dsi_device *dsi,
> > > > const void *data, size_t len);
> > > > +ssize_t mipi_dsi_dcs_write_buffer_chatty(struct mipi_dsi_device *dsi,
> > > > + const void *data, size_t len);
> > > > ssize_t mipi_dsi_dcs_write(struct mipi_dsi_device *dsi, u8 cmd,
> > > > const void *data, size_t len);
> > > > ssize_t mipi_dsi_dcs_read(struct mipi_dsi_device *dsi, u8 cmd, void *data,
> > > > @@ -317,14 +321,10 @@ int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi,
> > > > #define mipi_dsi_generic_write_seq(dsi, seq...) \
> > > > do { \
> > > > static const u8 d[] = { seq }; \
> > > > - struct device *dev = &dsi->dev; \
> > > > int ret; \
> > > > - ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d)); \
> > > > - if (ret < 0) { \
> > > > - dev_err_ratelimited(dev, "transmit data failed: %d\n", \
> > > > - ret); \
> > > > + ret = mipi_dsi_generic_write_chatty(dsi, d, ARRAY_SIZE(d)); \
> > > > + if (ret < 0) \
> > > > return ret; \
> > > > - } \
> > > > } while (0)
>
>
> Reading the thread makes me wonder whether we should be going into
> slightly other direction:
>
> Add __must_check() to mipi_dsi_ writing functions,
>
> #define mipi_dsi_dcs_whatever_write(dsi, cmd, seq...) \
> ({ \
> static const u8 d[] = { cmd, seq }; \
> mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)); \
> })
>
> Then in panel drivers we actually have to explicitly handle the return
> code (either by dropping to the error label or by just returning an
> error).
Given the sheer number of init commands needed by some panels (see
j606f_boe_init_sequence() for instance) I'm still convinced that we
want something that allows people to write their init code in a way
that's not quite so verbose. It sounds as if Jani is OK w/ the
proposal of using the "accumulated return value" (proposal #2 I had).
I'm hoping you're OK w/ that too...
-Doug
