[PATCH 3/4] [resend] fb_ddc: Allow I2C adapters without SCL read capability

Ondrej Zary
2015-03-22T19:56:03Z

i2c-algo-bit allows I2C adapters without SCL read capability to work but
fb_ddc_read fails to work on them.

Fix fb_ddc_read to work with I2C adapters not capable of reading SCL.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
---
drivers/video/fbdev/core/fb_ddc.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fbdev/core/fb_ddc.c b/drivers/video/fbdev/core/fb_ddc.c
index 94322cc..22c694a 100644
--- a/drivers/video/fbdev/core/fb_ddc.c
+++ b/drivers/video/fbdev/core/fb_ddc.c
@@ -69,10 +69,11 @@ unsigned char *fb_ddc_read(struct i2c_adapter *adapter)
algo_data->setscl(algo_data->data, 1);
for (j = 0; j < 5; j++) {
msleep(10);
- if (algo_data->getscl(algo_data->data))
+ if (algo_data->getscl &&
+ algo_data->getscl(algo_data->data))
break;
}
- if (j == 5)
+ if (algo_data->getscl && j == 5)
continue;

algo_data->setsda(algo_data->data, 0);
@@ -91,7 +92,8 @@ unsigned char *fb_ddc_read(struct i2c_adapter *adapter)
algo_data->setscl(algo_data->data, 1);
for (j = 0; j < 10; j++) {
msleep(10);
- if (algo_data->getscl(algo_data->data))
+ if (algo_data->getscl &&
+ algo_data->getscl(algo_data->data))
break;
}

--
Ondrej Zary