SD50 freq clock -> wifi sd8797
From: John Tobias <hidden>
Date: 2014-06-23 21:29:37
Hello Guys, I am using kernel 3.13 for iMX6SL and my wifi is a Marvell SD8797 wifi/bluetooth module. The sdhci-esdhc-imx controller configured it as follows: clock: 100000000 Hz actual clock: 99000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 5 (sd uhs SDR50) signal voltage: 0 (1.80 V) The above configuration works, but running (continuously) the wifi and the bluetooth at the same time (e.g. ping google.com and hcitool scan) caused it to get "mmc1: Timeout waiting for hardware interrupt." after 80+ loops. I used an SDIO 3 analyzer and I got a frequency captured 99Mhz and 102Mhz. But, I found a lot of CRC16 errors when the above frequency setting is being used. Then, I changed the frequency value to 90000000 (see below) in device tree. I pinging google.com and running hcitool scan (continuously) for almost 4 days and did not get the mmc1 timeout. Updated clock: clock: 90000000 Hz actual clock: 66000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 5 (sd uhs SDR50) signal voltage: 0 (1.80 V) Is there any existing issue/errata that I should aware of with regards to the sdhci-esdhc-imx controller particularly to those device need a 100Mhz frequency clock?. Regards, john