From 05f3e58b8633590b1319db22646dd78ba6de2660 Mon Sep 17 00:00:00 2001 From: Johan Fjeldtvedt Date: Mon, 22 Aug 2016 06:04:52 -0300 Subject: [PATCH] [media] pulse8-cec: serialize communication with adapter Make sending messages to the adapter serialized within the driver. send_and_wait is split into send_and_wait_once, which only sends once and checks for the result, and the higher level send_and_wait, which performs locking and retries. Signed-off-by: Johan Fjeldtvedt Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/media/pulse8-cec/pulse8-cec.c | 52 ++++++++++++------- 1 file changed, 32 insertions(+), 20 deletions(-) diff --git a/drivers/staging/media/pulse8-cec/pulse8-cec.c b/drivers/staging/media/pulse8-cec/pulse8-cec.c index 94f8590492dc..dcda68a569a7 100644 --- a/drivers/staging/media/pulse8-cec/pulse8-cec.c +++ b/drivers/staging/media/pulse8-cec/pulse8-cec.c @@ -99,6 +99,7 @@ struct pulse8 { unsigned int idx; bool escape; bool started; + struct mutex write_lock; }; static void pulse8_irq_work_handler(struct work_struct *work) @@ -233,8 +234,9 @@ static int pulse8_send(struct serio *serio, const u8 *command, u8 cmd_len) return err; } -static int pulse8_send_and_wait(struct pulse8 *pulse8, - const u8 *cmd, u8 cmd_len, u8 response, u8 size) +static int pulse8_send_and_wait_once(struct pulse8 *pulse8, + const u8 *cmd, u8 cmd_len, + u8 response, u8 size) { int err; @@ -250,24 +252,8 @@ static int pulse8_send_and_wait(struct pulse8 *pulse8, if ((pulse8->data[0] & 0x3f) == MSGCODE_COMMAND_REJECTED && cmd[0] != MSGCODE_SET_CONTROLLED && cmd[0] != MSGCODE_SET_AUTO_ENABLED && - cmd[0] != MSGCODE_GET_BUILDDATE) { - u8 cmd_sc[2]; - - cmd_sc[0] = MSGCODE_SET_CONTROLLED; - cmd_sc[1] = 1; - err = pulse8_send_and_wait(pulse8, cmd_sc, 2, - MSGCODE_COMMAND_ACCEPTED, 1); - if (err) - return err; - init_completion(&pulse8->cmd_done); - - err = pulse8_send(pulse8->serio, cmd, cmd_len); - if (err) - return err; - - if (!wait_for_completion_timeout(&pulse8->cmd_done, HZ)) - return -ETIMEDOUT; - } + cmd[0] != MSGCODE_GET_BUILDDATE) + return -ENOTTY; if (response && ((pulse8->data[0] & 0x3f) != response || pulse8->len < size + 1)) { dev_info(pulse8->dev, "transmit: failed %02x\n", @@ -277,6 +263,31 @@ static int pulse8_send_and_wait(struct pulse8 *pulse8, return 0; } +static int pulse8_send_and_wait(struct pulse8 *pulse8, + const u8 *cmd, u8 cmd_len, u8 response, u8 size) +{ + u8 cmd_sc[2]; + int err; + + mutex_lock(&pulse8->write_lock); + err = pulse8_send_and_wait_once(pulse8, cmd, cmd_len, response, size); + + if (err == -ENOTTY) { + cmd_sc[0] = MSGCODE_SET_CONTROLLED; + cmd_sc[1] = 1; + err = pulse8_send_and_wait_once(pulse8, cmd_sc, 2, + MSGCODE_COMMAND_ACCEPTED, 1); + if (err) + goto unlock; + err = pulse8_send_and_wait_once(pulse8, cmd, cmd_len, + response, size); + } + +unlock: + mutex_unlock(&pulse8->write_lock); + return err == -ENOTTY ? -EIO : err; +} + static int pulse8_setup(struct pulse8 *pulse8, struct serio *serio) { u8 *data = pulse8->data + 1; @@ -453,6 +464,7 @@ static int pulse8_connect(struct serio *serio, struct serio_driver *drv) pulse8->dev = &serio->dev; serio_set_drvdata(serio, pulse8); INIT_WORK(&pulse8->work, pulse8_irq_work_handler); + mutex_init(&pulse8->write_lock); err = serio_open(serio, drv); if (err)