From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ondrej Zary Date: Wed, 02 Sep 2015 12:04:51 +0000 Subject: Re: [PATCH 3/4] [resend #2] fb_ddc: Allow I2C adapters without SCL read capability Message-Id: <201509021404.51232.linux@rainbow-software.org> List-Id: References: <1440445048-24694-1-git-send-email-linux@rainbow-software.org> <1440445048-24694-3-git-send-email-linux@rainbow-software.org> <55E6DE7D.9060700@ti.com> In-Reply-To: <55E6DE7D.9060700@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tomi Valkeinen Cc: Krzysztof Helt , linux-fbdev@vger.kernel.org, Kernel development list On Wednesday 02 September 2015, Tomi Valkeinen wrote: > On 24/08/15 22:37, Ondrej Zary wrote: > > 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; > > } > > Aren't both of those loops pointless if there's no getscl? They're reduced to delays - don't know how much critical they are. -- Ondrej Zary