Commit a87a6d6b authored by Tomi Valkeinen's avatar Tomi Valkeinen
Browse files

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: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
parent fa0c52ab

drivers/video/fbdev/omap2/displays-new/encoder-tpd12s015.c

+10 −47
Original line number Diff line number Diff line
@@ -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;