| Message ID | 20221214125821.12489-6-paul@crapouillou.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: bridge: it66121: IT6610 support and cleanups | expand |
On Wed, 14 Dec 2022 at 13:59, Paul Cercueil <paul@crapouillou.net> wrote: > > The function it66121_wait_ddc_ready() would previously read the status > register until "true", which means it never actually polled anything and > would just read the register once. > > Now, it will properly wait until the DDC hardware is ready or until it > reported an error. > > The 'busy' variable was also renamed to 'error' since these bits are set > on error and not when the DDC hardware is busy. > > Since the DDC ready function is now working properly, the msleep(20) can > be removed. > > Signed-off-by: Paul Cercueil <paul@crapouillou.net> > --- > drivers/gpu/drm/bridge/ite-it66121.c | 15 +++++++-------- > 1 file changed, 7 insertions(+), 8 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c > index 0a4fdfd7af44..bfb9c87a7019 100644 > --- a/drivers/gpu/drm/bridge/ite-it66121.c > +++ b/drivers/gpu/drm/bridge/ite-it66121.c > @@ -440,15 +440,17 @@ static int it66121_configure_afe(struct it66121_ctx *ctx, > static inline int it66121_wait_ddc_ready(struct it66121_ctx *ctx) > { > int ret, val; > - u32 busy = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS | > - IT66121_DDC_STATUS_ARBI_LOSE; > + u32 error = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS | > + IT66121_DDC_STATUS_ARBI_LOSE; > + u32 done = IT66121_DDC_STATUS_TX_DONE; > > - ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val, true, > - IT66121_EDID_SLEEP_US, IT66121_EDID_TIMEOUT_US); > + ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val, > + val & (error | done), IT66121_EDID_SLEEP_US, > + IT66121_EDID_TIMEOUT_US); > if (ret) > return ret; > > - if (val & busy) > + if (val & error) > return -EAGAIN; > > return 0; > @@ -582,9 +584,6 @@ static int it66121_get_edid_block(void *context, u8 *buf, > offset += cnt; > remain -= cnt; > > - /* Per programming manual, sleep here before emptying the FIFO */ > - msleep(20); > - > ret = it66121_wait_ddc_ready(ctx); > if (ret) > return ret; > -- > 2.35.1 > Reviewed-by: Robert Foss <robert.foss@linaro.org>
diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c index 0a4fdfd7af44..bfb9c87a7019 100644 --- a/drivers/gpu/drm/bridge/ite-it66121.c +++ b/drivers/gpu/drm/bridge/ite-it66121.c @@ -440,15 +440,17 @@ static int it66121_configure_afe(struct it66121_ctx *ctx, static inline int it66121_wait_ddc_ready(struct it66121_ctx *ctx) { int ret, val; - u32 busy = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS | - IT66121_DDC_STATUS_ARBI_LOSE; + u32 error = IT66121_DDC_STATUS_NOACK | IT66121_DDC_STATUS_WAIT_BUS | + IT66121_DDC_STATUS_ARBI_LOSE; + u32 done = IT66121_DDC_STATUS_TX_DONE; - ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val, true, - IT66121_EDID_SLEEP_US, IT66121_EDID_TIMEOUT_US); + ret = regmap_read_poll_timeout(ctx->regmap, IT66121_DDC_STATUS_REG, val, + val & (error | done), IT66121_EDID_SLEEP_US, + IT66121_EDID_TIMEOUT_US); if (ret) return ret; - if (val & busy) + if (val & error) return -EAGAIN; return 0; @@ -582,9 +584,6 @@ static int it66121_get_edid_block(void *context, u8 *buf, offset += cnt; remain -= cnt; - /* Per programming manual, sleep here before emptying the FIFO */ - msleep(20); - ret = it66121_wait_ddc_ready(ctx); if (ret) return ret;
The function it66121_wait_ddc_ready() would previously read the status register until "true", which means it never actually polled anything and would just read the register once. Now, it will properly wait until the DDC hardware is ready or until it reported an error. The 'busy' variable was also renamed to 'error' since these bits are set on error and not when the DDC hardware is busy. Since the DDC ready function is now working properly, the msleep(20) can be removed. Signed-off-by: Paul Cercueil <paul@crapouillou.net> --- drivers/gpu/drm/bridge/ite-it66121.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)