Re: Downgrade GSM/UMTS module to USB 2.0 Fullspeed
Hello Oliver, Am 18.01.2017 um 17:05 schrieb Oliver Graute: > Hello list, > > i'am using a GSM/UMTS Module on a PCB which is connected with USB 2.0 > Hi-Speed to my imx6ul CPU. To reduce our Electromagnetic compatibility > and to make my hardware colleges happy again I want to downgrade to USB > Full Speed. i think this topic fits better into the i.MX Community [1] Regards Stefan [1] - https://community.nxp.com/community/imx ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Downgrade GSM/UMTS module to USB 2.0 Fullspeed
On Wed, Jan 18, 2017 at 05:05:34PM +0100, Oliver Graute wrote: > Hello list, > > i'am using a GSM/UMTS Module on a PCB which is connected with USB 2.0 > Hi-Speed to my imx6ul CPU. To reduce our Electromagnetic compatibility > and to make my hardware colleges happy again I want to downgrade to USB > Full Speed. > > How can I tell the Linux Kernel to Do so? You can't. It's up to the device to tell the host what "speed" it is running at. See the USB spec for all of the crazy details. I suggest you modify the firmware of your modem to do this, that's the only way it is going to work (note, your device needs to be able to support full speed, it might not be able to do that.) good luck! greg k-h ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Downgrade GSM/UMTS module to USB 2.0 Fullspeed
Hello list, i'am using a GSM/UMTS Module on a PCB which is connected with USB 2.0 Hi-Speed to my imx6ul CPU. To reduce our Electromagnetic compatibility and to make my hardware colleges happy again I want to downgrade to USB Full Speed. How can I tell the Linux Kernel to Do so? I already tried this and looked around in /sys/bus/usb/devices but can't find appropirate place to force it to lower speed. dmesg | grep USB [ 175.775175] usb 1-1: new high-speed USB device number 2 using ci_hdrc [ 175.938753] usb 1-1: New USB device found, idVendor=1e2d, idProduct=005a [ 175.938797] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 176.021420] cdc_acm 1-1:1.0: ttyACM0: USB ACM device [ 176.068150] cdc_acm 1-1:1.2: ttyACM1: USB ACM device [ 176.102410] cdc_acm 1-1:1.4: ttyACM2: USB ACM device [ 176.131074] cdc_acm 1-1:1.6: ttyACM3: USB ACM device [ 176.172841] cdc_acm 1-1:1.11: ttyACM4: USB ACM device [ 176.208768] cdc_acm 1-1:1.13: ttyACM5: USB ACM device /sys/bus/usb/devices# lsusb -t /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ci_hdrc/1p, 480M |__ Port 1: Dev 2, If 0, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 1, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 2, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 3, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 4, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 5, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 6, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 7, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 8, Class=, Driver=, 480M |__ Port 1: Dev 2, If 9, Class=, Driver=, 480M |__ Port 1: Dev 2, If 10, Class=, Driver=, 480M |__ Port 1: Dev 2, If 11, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 12, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 13, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 14, Class=, Driver=cdc_acm, 480M |__ Port 1: Dev 2, If 15, Class=, Driver=, 480M Best Regards, Oliver ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
How to identify the cause of " BUG: Bad page map in process python ..." kernel errors?
Hi All, I am observing the following statements in the kernel log while running driver soak tests and monitoring MIPS and memory usage: [ 8350.824403] BUG: Bad page map in process python pte:00c0 pmd:950a5067 [ 8351.457234] BUG: Bad page map in process python pte:34000c0 pmd:950a5067 [ 8351.458469] BUG: Bad page map in process python pte:406486b3be206e97 pmd:950a5067 …. [ 8353.266053] BUG: Bad page map in process python pte:406486b3fb696e97 pmd:950a5067 [ 8353.305982] BUG: Bad page map in process python pte:00c0 pmd:950a5067 [ 8355.738440] BUG: Bad rss-counter state mm:880138fa7100 idx:1 val:259 [ 8374.905314] general protection fault: [#1] SMP In the kernel log, I observed that kernel reported 60 " BUG: Bad page map in process python ..." reports and 1 “BUG: Bad rss-counter state” and finally it crashed with “general protection fault”. I would like to know what does it mean by “BUG: Bad page map in process python ...” and how to identify the cause of it? To debug this, do I need to consider the “general protection fault” stack trace or the first “BUG: Bad page map in process …” stack trace? -- Thanks, Sekhar ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
ioremap of large space has any cost ?
Hello, In case where we have large space (like in fpga), we thought of using ioremap_nocache() giving the complete area space for simplicity. But does it has any cost (performance, memory or other) , or is it better to use just chunk of the required space ? Thank you, Ran ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
