From 5022a2088687baeda87b03889d0791b1b908266b Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 27 Dec 2013 00:28:57 -0300 Subject: [PATCH] [media] em28xx: properly implement AC97 wait code MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Instead of assuming that msleep() is precise, use a jiffies based code to wait for AC97 to be available. Reviewed-by: Frank Schäfer Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-core.c | 7 +++++-- drivers/media/usb/em28xx/em28xx.h | 3 +++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c index b5f49703f7ce..b6dc3327c51c 100644 --- a/drivers/media/usb/em28xx/em28xx-core.c +++ b/drivers/media/usb/em28xx/em28xx-core.c @@ -23,6 +23,7 @@ */ #include +#include #include #include #include @@ -252,16 +253,18 @@ EXPORT_SYMBOL_GPL(em28xx_toggle_reg_bits); */ static int em28xx_is_ac97_ready(struct em28xx *dev) { - int ret, i; + unsigned long timeout = jiffies + msecs_to_jiffies(EM28XX_AC97_XFER_TIMEOUT); + int ret; /* Wait up to 50 ms for AC97 command to complete */ - for (i = 0; i < 10; i++, msleep(5)) { + while (time_is_after_jiffies(timeout)) { ret = em28xx_read_reg(dev, EM28XX_R43_AC97BUSY); if (ret < 0) return ret; if (!(ret & 0x01)) return 0; + msleep(5); } em28xx_warn("AC97 command still being executed: not handled properly!\n"); diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h index b792f2225abd..b0aa8497c1a9 100644 --- a/drivers/media/usb/em28xx/em28xx.h +++ b/drivers/media/usb/em28xx/em28xx.h @@ -186,6 +186,9 @@ /* time in msecs to wait for i2c writes to finish */ #define EM2800_I2C_XFER_TIMEOUT 20 +/* time in msecs to wait for AC97 xfers to finish */ +#define EM28XX_AC97_XFER_TIMEOUT 100 + /* max. number of button state polling addresses */ #define EM28XX_NUM_BUTTON_ADDRESSES_MAX 5 -- 2.30.2