OMAPDSS: encoder-tpd12s015: Fix race issue with LS_OE

A race issue has been observed with the encoder-tpd12s015 driver, which
leads to errors when trying to read EDID. This has only now been
observed, as OMAP4 and OMAP5 boards used SoC's GPIOs for LS_OE GPIO. On
dra7-evm boards, the LS_OE is behind a i2c controlled GPIO expander,
which increases the time to set the LS_OE.

This patch simplifies the handling of the LS_OE gpio in the driver by
removing the interrupt handling totally. The only time we actually need
to enable LS_OE is when we are reading the EDID, and thus we can just
set and clear the LS_OE gpio inside the read_edid() function.

This also has the additional benefit of very slightly decreasing the
power consumption.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 10 insertions, 47 deletions

diff --git a/drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c b/drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c
index 7f3e11b16c86..990af6baeb0f 100644
--- a/drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c
+++ b/drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c
@@ -29,33 +29,10 @@ struct panel_drv_data {
         int hpd_gpio;
 
         struct omap_video_timings timings;
-
-        struct completion hpd_completion;
 };
 
 #define to_panel_data(x) container_of(x, struct panel_drv_data, dssdev)
 
-static irqreturn_t tpd_hpd_irq_handler(int irq, void *data)
-{
-        struct panel_drv_data *ddata = data;
-        bool hpd;
-
-        hpd = gpio_get_value_cansleep(ddata->hpd_gpio);
-
-        dev_dbg(ddata->dssdev.dev, "hpd %d\n", hpd);
-
-        if (gpio_is_valid(ddata->ls_oe_gpio)) {
-                if (hpd)
-                        gpio_set_value_cansleep(ddata->ls_oe_gpio, 1);
-                else
-                        gpio_set_value_cansleep(ddata->ls_oe_gpio, 0);
-        }
-
-        complete_all(&ddata->hpd_completion);
-
-        return IRQ_HANDLED;
-}
-
 static int tpd_connect(struct omap_dss_device *dssdev,
                 struct omap_dss_device *dst)
 {
@@ -70,23 +47,10 @@ static int tpd_connect(struct omap_dss_device *dssdev,
         dst->src = dssdev;
         dssdev->dst = dst;
 
-        reinit_completion(&ddata->hpd_completion);
-
         gpio_set_value_cansleep(ddata->ct_cp_hpd_gpio, 1);
         /* DC-DC converter needs at max 300us to get to 90% of 5V */
         udelay(300);
 
-        /*
-         * If there's a cable connected, wait for the hpd irq to trigger,
-         * which turns on the level shifters.
-         */
-        if (gpio_get_value_cansleep(ddata->hpd_gpio)) {
-                unsigned long to;
-                to = wait_for_completion_timeout(&ddata->hpd_completion,
-                                msecs_to_jiffies(250));
-                WARN_ON_ONCE(to == 0);
-        }
-
         return 0;
 }
 
@@ -179,11 +143,20 @@ static int tpd_read_edid(struct omap_dss_device *dssdev,
 {
         struct panel_drv_data *ddata = to_panel_data(dssdev);
         struct omap_dss_device *in = ddata->in;
+        int r;
 
         if (!gpio_get_value_cansleep(ddata->hpd_gpio))
                 return -ENODEV;
 
-        return in->ops.hdmi->read_edid(in, edid, len);
+        if (gpio_is_valid(ddata->ls_oe_gpio))
+                gpio_set_value_cansleep(ddata->ls_oe_gpio, 1);
+
+        r = in->ops.hdmi->read_edid(in, edid, len);
+
+        if (gpio_is_valid(ddata->ls_oe_gpio))
+                gpio_set_value_cansleep(ddata->ls_oe_gpio, 0);
+
+        return r;
 }
 
 static bool tpd_detect(struct omap_dss_device *dssdev)
@@ -309,8 +282,6 @@ static int tpd_probe(struct platform_device *pdev)
 
         platform_set_drvdata(pdev, ddata);
 
-        init_completion(&ddata->hpd_completion);
-
         if (dev_get_platdata(&pdev->dev)) {
                 r = tpd_probe_pdata(pdev);
                 if (r)
@@ -340,13 +311,6 @@ static int tpd_probe(struct platform_device *pdev)
         if (r)
                 goto err_gpio;
 
-        r = devm_request_threaded_irq(&pdev->dev, gpio_to_irq(ddata->hpd_gpio),
-                                 NULL, tpd_hpd_irq_handler,
-                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
-                                 IRQF_ONESHOT, "hpd", ddata);
-        if (r)
-                goto err_irq;
-
         dssdev = &ddata->dssdev;
         dssdev->ops.hdmi = &tpd_hdmi_ops;
         dssdev->dev = &pdev->dev;
@@ -365,7 +329,6 @@ static int tpd_probe(struct platform_device *pdev)
 
         return 0;
 err_reg:
-err_irq:
 err_gpio:
         omap_dss_put_device(ddata->in);
         return r;