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authorFabio Estevam <fabio.estevam@freescale.com>2013-07-01 18:14:21 -0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-08-14 22:59:06 -0700
commit060a7c36d7ba82d7f520d7f328db5d38e99c20a4 (patch)
tree7f1ccae277d008588caf1f02ec1e88fa509703d6
parent630d2243751d762ea9e1baabecd6536e9db8d0be (diff)
downloadvexpress-lsk-060a7c36d7ba82d7f520d7f328db5d38e99c20a4.tar.gz
i2c: i2c-mxs: Use DMA mode even for small transfers
commit d6e102f498cbcc8dd2e36721a01213f036397112 upstream. Recently we have been seing some reports about PIO mode not working properly. - http://www.spinics.net/lists/linux-i2c/msg11985.html - http://marc.info/?l=linux-i2c&m=137235593101385&w=2 - https://lkml.org/lkml/2013/6/24/430 Let's use DMA mode even for small transfers. Without this patch, i2c reads the incorrect sgtl5000 version on a mx28evk when touchscreen is enabled: [ 5.856270] sgtl5000 0-000a: Device with ID register 0 is not a sgtl5000 [ 9.877307] sgtl5000 0-000a: ASoC: failed to probe CODEC -19 [ 9.883528] mxs-sgtl5000 sound.12: ASoC: failed to instantiate card -19 [ 9.892955] mxs-sgtl5000 sound.12: snd_soc_register_card failed (-19) [wsa: we have a proper solution for -next, so this non intrusive solution is OK for now] Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Shawn Guo <shawn.guo@linaro.org> Acked-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Marek Vasut <marex@denx.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/i2c/busses/i2c-mxs.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 2039f230482..6d8094d4498 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -494,7 +494,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
* based on this empirical measurement and a lot of previous frobbing.
*/
i2c->cmd_err = 0;
- if (msg->len < 8) {
+ if (0) { /* disable PIO mode until a proper fix is made */
ret = mxs_i2c_pio_setup_xfer(adap, msg, flags);
if (ret)
mxs_i2c_reset(i2c);