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Subject[PATCH 01/12] ipack/devices/ipoctal: Fix race condition during Tx
Date
From: Alberto Garcia <agarcia@igalia.com>

In order to transmit data, the driver enables Tx and sleeps until
*board_write is set to 1 by the interrupt handler.

It can happen, though, that the data is sent even before the process
is asleep. In this case *board_write must be set to 1 anyway,
otherwise we will be waiting for a condition that will never be true.

Signed-off-by: Alberto Garcia <agarcia@igalia.com>
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
---
drivers/ipack/devices/ipoctal.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index c06ab39..b312863 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -195,13 +195,10 @@ static void ipoctal_irq_tx(struct ipoctal_channel *channel)
*pointer_write = *pointer_write % PAGE_SIZE;
channel->nb_bytes--;

- if ((channel->nb_bytes == 0) &&
- (waitqueue_active(&channel->queue))) {
-
- if (channel->board_id != IPACK1_DEVICE_ID_SBS_OCTAL_485) {
- *channel->board_write = 1;
- wake_up_interruptible(&channel->queue);
- }
+ if (channel->nb_bytes == 0 &&
+ channel->board_id != IPACK1_DEVICE_ID_SBS_OCTAL_485) {
+ *channel->board_write = 1;
+ wake_up_interruptible(&channel->queue);
}
}

--
1.7.10.4


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