# \[PATCH 3/4\] \[resend \#2\] fb\_ddc: Allow I2C adapters without SCL read capability - From: Ondrej Zary \ - Date: 2015-08-24 19:37:57 - List: linux-fbdev - Page: https://ratatoskr.run/linux-fbdev/2015/08/4563092 - Thread: https://ratatoskr.run/linux-fbdev/2015/08/4563090/t.md ```text 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 Acked-by: Krzysztof Helt --- 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 ```