From: Antti Palosaari <crope@iki.fi>
To: linux-media@vger.kernel.org
Cc: Antti Palosaari <crope@iki.fi>
Subject: [PATCH 1/2] rtl28xxu: return demod reg page from driver cache
Date: Sun, 20 Dec 2015 04:03:34 +0200 [thread overview]
Message-ID: <1450577015-29465-1-git-send-email-crope@iki.fi> (raw)
Return current active rtl2830/rtl2832 register page from the driver
cache in order to reduce I2C I/O. Register page is already cached
due to I2C write needs.
Signed-off-by: Antti Palosaari <crope@iki.fi>
---
drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
index 5a503a6..eb5787a 100644
--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
@@ -181,11 +181,17 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[],
goto err_mutex_unlock;
} else if (msg[0].addr == 0x10) {
/* method 1 - integrated demod */
- req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1);
- req.index = CMD_DEMOD_RD | dev->page;
- req.size = msg[1].len;
- req.data = &msg[1].buf[0];
- ret = rtl28xxu_ctrl_msg(d, &req);
+ if (msg[0].buf[0] == 0x00) {
+ /* return demod page from driver cache */
+ msg[1].buf[0] = dev->page;
+ ret = 0;
+ } else {
+ req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1);
+ req.index = CMD_DEMOD_RD | dev->page;
+ req.size = msg[1].len;
+ req.data = &msg[1].buf[0];
+ ret = rtl28xxu_ctrl_msg(d, &req);
+ }
} else if (msg[0].len < 2) {
/* method 2 - old I2C */
req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1);
--
http://palosaari.fi/
next reply other threads:[~2015-12-20 2:03 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-20 2:03 Antti Palosaari [this message]
2015-12-20 2:03 ` [PATCH 2/2] rtl2832: print reg number on error case Antti Palosaari
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