Re: [PATCH 1/3] drm/bridge: ti-sn65dsi86: Simplify refclk handling

Hey Douglas,

Thanks for submitting this cleanup, it looks good to me.

Reviewed-by: Robert Foss robert.foss@linaro.org

On Fri, 5 Mar 2021 at 00:53, Douglas Anderson dianders@chromium.org wrote:

The clock framework makes it simple to deal with an optional clock. You can call clk_get_optional() and if the clock isn't specified it'll just return NULL without complaint. It's valid to pass NULL to enable/disable/prepare/unprepare. Let's make use of this to simplify things a tiny bit.

NOTE: this makes things look a tad bit asymmetric now since we check for NULL before clk_prepare_enable() but not for clk_disable_unprepare(). This seemed OK to me. We already have to check for NULL in the enable case anyway so why not avoid the extra call?

I think this is fine. Since the refclk != NULL check in ti_sn_bridge_set_refclk_freq is in order to determine other behaviour, the asymmetry is required.

Signed-off-by: Douglas Anderson dianders@chromium.org

drivers/gpu/drm/bridge/ti-sn65dsi86.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index f27306c51e4d..942019842ff4 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -1261,14 +1261,9 @@ static int ti_sn_bridge_probe(struct i2c_client *client, return ret; }

•   pdata->refclk = devm_clk_get(pdata->dev, "refclk");
  

•   if (IS_ERR(pdata->refclk)) {
  

•           ret = PTR_ERR(pdata->refclk);
  

•           if (ret == -EPROBE_DEFER)
  

•                   return ret;
  

•           DRM_DEBUG_KMS("refclk not found\n");
  

•           pdata->refclk = NULL;
  

•   }
  

•   pdata->refclk = devm_clk_get_optional(pdata->dev, "refclk");
  

•   if (IS_ERR(pdata->refclk))
  

•           return PTR_ERR(pdata->refclk);
  
    ret = ti_sn_bridge_parse_dsi_host(pdata);
    if (ret)
  

-- 2.30.1.766.gb4fecdf3b7-goog