Attachment 70989 Details for Bug 57834 – uru4000: fix race condition on waiting power up irq

[patch] uru4000: fix race condition on waiting power up irq

0001-uru4000-fix-race-condition-on-waiting-power-up-irq.patch (text/plain), 2.59 KB, created by Timo Teräs on 2012-12-04 08:53:22 UTC

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Creator: Timo Teräs

Created: 2012-12-04 08:53:22 UTC

Size: 2.59 KB

patch

obsolete

>From 40e66424e9d2a3d03b14057fecc583e6f0be6ad5 Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
>Date: Tue, 4 Dec 2012 10:50:30 +0200
>Subject: [PATCH] uru4000: fix race condition on waiting power up irq
>
>It can come before we finish reading the status register on some
>cases. Arm the irq handler early, and fix the state machine to
>handle early irq properly.
>---
> libfprint/drivers/uru4000.c | 31 ++++++++++++++++++++-----------
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
>diff --git a/libfprint/drivers/uru4000.c b/libfprint/drivers/uru4000.c
>index d9ee236..ccaa87f 100644
>--- a/libfprint/drivers/uru4000.c
>+++ b/libfprint/drivers/uru4000.c
>@@ -997,16 +997,19 @@ static void init_scanpwr_irq_cb(struct fp_img_dev *dev, int status,
> 	uint16_t type, void *user_data)
> {
> 	struct fpi_ssm *ssm = user_data;
>+	struct uru4k_dev *urudev = dev->priv;
> 
> 	if (status)
> 		fpi_ssm_mark_aborted(ssm, status);
> 	else if (type != IRQDATA_SCANPWR_ON)
> 		fp_dbg("ignoring interrupt");
>-	else if (ssm->cur_state != INIT_AWAIT_SCAN_POWER)
>-		fp_err("ignoring scanpwr interrupt due to being in wrong state %d",
>-			ssm->cur_state);
>-	else
>+	else if (ssm->cur_state != INIT_AWAIT_SCAN_POWER) {
>+		fp_dbg("early scanpwr interrupt");
>+		urudev->scanpwr_irq_timeouts = -1;
>+	} else {
>+		fp_dbg("late scanpwr interrupt");
> 		fpi_ssm_next_state(ssm);
>+	}
> }
> 
> static void init_scanpwr_timeout(void *user_data)
>@@ -1056,14 +1059,21 @@ static void init_run_state(struct fpi_ssm *ssm)
> 			fpi_ssm_next_state(ssm);
> 		break;
> 	case INIT_POWERUP: ;
>+		if (!IRQ_HANDLER_IS_RUNNING(urudev)) {
>+			fpi_ssm_mark_aborted(ssm, -EIO);
>+			break;
>+		}
>+		urudev->irq_cb_data = ssm;
>+		urudev->irq_cb = init_scanpwr_irq_cb;
>+
> 		struct fpi_ssm *powerupsm = fpi_ssm_new(dev->dev, powerup_run_state,
> 			POWERUP_NUM_STATES);
> 		powerupsm->priv = dev;
> 		fpi_ssm_start_subsm(ssm, powerupsm);
> 		break;
> 	case INIT_AWAIT_SCAN_POWER:
>-		if (!IRQ_HANDLER_IS_RUNNING(urudev)) {
>-			fpi_ssm_mark_aborted(ssm, -EIO);
>+		if (urudev->scanpwr_irq_timeouts < 0) {
>+			fpi_ssm_next_state(ssm);
> 			break;
> 		}
> 
>@@ -1076,13 +1086,12 @@ static void init_run_state(struct fpi_ssm *ssm)
> 			fpi_ssm_mark_aborted(ssm, -ETIME);
> 			break;
> 		}
>-
>-		urudev->irq_cb_data = ssm;
>-		urudev->irq_cb = init_scanpwr_irq_cb;
> 		break;
> 	case INIT_DONE:
>-		fpi_timeout_cancel(urudev->scanpwr_irq_timeout);
>-		urudev->scanpwr_irq_timeout = NULL;
>+		if (urudev->scanpwr_irq_timeout) {
>+			fpi_timeout_cancel(urudev->scanpwr_irq_timeout);
>+			urudev->scanpwr_irq_timeout = NULL;
>+		}
> 		urudev->irq_cb_data = NULL;
> 		urudev->irq_cb = NULL;
> 		fpi_ssm_next_state(ssm);
>-- 
>1.8.0.1
>

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