On 19 February 2015 at 18:14, Antti Palosaari <crope@xxxxxx> wrote: > On 02/19/2015 06:01 PM, Antti Seppälä wrote: >> >> On 19 February 2015 at 17:38, Antti Palosaari <crope@xxxxxx> wrote: >>> >>> On 02/19/2015 12:21 PM, Antti Seppälä wrote: >>>> >>>> On 19 February 2015 at 11:43, Benjamin Larsson <benjamin@xxxxxxxxxxxx> >>>> wrote: >>>>> >>>>> >>>>> On 2015-02-19 10:13, Antti Seppälä wrote: >>>>>> >>>>>> >>>>>> >>>>>> It seems that currently the firmware download on the mn88472 is >>>>>> somehow wrong for my Astrometa HD-901T2. >>>>>> >>>>>> Reducing the download chunk size (mn88472_config.i2c_wr_max) to 2 >>>>>> makes the firmware download consistently succeed. >>>>>> >>>>> >>>>> >>>>> Hi, try adding the workaround patch I sent for this. >>>>> >>>>> [PATCH 1/3] rtl28xxu: lower the rc poll time to mitigate i2c transfer >>>>> errors >>>>> >>>>> I now see that it hasn't been merged. But I have been running with this >>>>> patch for a few months now without any major issues. >>>>> >>>> >>>> The patch really did improve firmware loading. Weird... >>>> >>>> Even with it I still get occasional i2c errors from r820t: >>>> >>>> [ 15.874402] r820t 8-003a: r820t_write: i2c wr failed=-32 reg=0a >>>> len=1: >>>> da >>>> [ 81.455517] r820t 8-003a: r820t_read: i2c rd failed=-32 reg=00 >>>> len=4: 69 74 e6 df >>>> [ 99.949702] r820t 8-003a: r820t_read: i2c rd failed=-32 reg=00 >>>> len=4: 69 74 e6 df >>>> >>>> These errors seem to appear more often if I'm reading the signal >>>> strength values using e.g. femon. >>> >>> >>> >>> Could you disable whole IR polling and test >>> modprobe dvb_usb_v2 disable_rc_polling=1 >>> >>> It is funny that *increasing* RC polling makes things better, though... >>> >> >> Hi. >> >> I tried loading the driver with polling disabled and it fails completely: >> >> [ 5526.693563] mn88472 7-0018: downloading firmware from file >> 'dvb-demod-mn88472-02.fw' >> [ 5527.032209] mn88472 7-0018: firmware download failed=-32 >> [ 5527.033864] rtl2832 7-0010: i2c reg write failed -32 >> [ 5527.033874] r820t 8-003a: r820t_write: i2c wr failed=-32 reg=05 len=1: >> 83 >> [ 5527.036014] rtl2832 7-0010: i2c reg write failed -32 >> >> I have no idea why the device behaves so counter-intuitively. Is there >> maybe some sorf of internal power-save mode the device enters when >> there is no i2c traffic for a while or something? > > > IR polling does not use I2C but some own commands. Could you make more > tests. Use rtl28xxu module parameter to disable IR and test. It will disable > both IR interrupts and polling. Then make some tests with different IR > polling intervals to see how it behaves. > Hi Antti. I made some further tests for you. Here are the results: dvb_usb_v2 disable_rc_polling=1: firmware download FAILED dvb_usb_rtl28xxu disable_rc=1: firmware download FAILED Then I restored the module parameters to default values and tested with various rc->interval values: interval = 800: firmware download FAILED interval = 600: firmware download FAILED interval = 400: firmware download FAILED interval = 300: firmware download SUCCESS but I2C errors from tuner could be sometimes observed interval = 200: firmware download SUCCESS interval = 100: firmware download SUCCESS So somehow higher rc polling rate makes the firmware download succeed. This could indeed be some locking/timing related bug. Please let me know if there is something else I can test. -Antti -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
