* Mauro Carvalho Chehab wrote: > Em 04-08-2011 04:14, Thierry Reding escreveu: > > The TM6010 supports much larger I2C transfers than currently specified. > > In fact the Windows driver seems to use 81 bytes per packet by default. > > This commit improves the speed of firmware loading a bit. > > --- > > drivers/staging/tm6000/tm6000-cards.c | 1 + > > drivers/staging/tm6000/tm6000-i2c.c | 2 +- > > 2 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/staging/tm6000/tm6000-cards.c > > b/drivers/staging/tm6000/tm6000-cards.c > > index c3b84c9..a5d2a71 100644 > > --- a/drivers/staging/tm6000/tm6000-cards.c > > +++ b/drivers/staging/tm6000/tm6000-cards.c > > @@ -929,6 +929,7 @@ static void tm6000_config_tuner(struct tm6000_core *dev) > > memset(&ctl, 0, sizeof(ctl)); > > > > ctl.demod = XC3028_FE_ZARLINK456; > > + ctl.max_len = 81; > > > > xc2028_cfg.tuner = TUNER_XC2028; > > xc2028_cfg.priv = &ctl; > > diff --git a/drivers/staging/tm6000/tm6000-i2c.c > > b/drivers/staging/tm6000/tm6000-i2c.c > > index 21cd9f8..2cb7573 100644 > > --- a/drivers/staging/tm6000/tm6000-i2c.c > > +++ b/drivers/staging/tm6000/tm6000-i2c.c > > @@ -50,7 +50,7 @@ static int tm6000_i2c_send_regs(struct tm6000_core *dev, > > unsigned char addr, > > unsigned int i2c_packet_limit = 16; > > > > if (dev->dev_type == TM6010) > > - i2c_packet_limit = 64; > > + i2c_packet_limit = 256; > > This shouldn't work fine. As said at USB 2.0 specification: > > An endpoint for control transfers specifies the maximum data payload > size that the endpoint can accept from > or transmit to the bus. The allowable maximum control transfer data > payload sizes for full-speed devices is > 8, 16, 32, or 64 bytes; for high-speed devices, it is 64 bytes and for > low-speed devices, it is 8 bytes. This > maximum applies to the data payloads of the Data packets following a > Setup; i.e., the size specified is for > the data field of the packet as defined in Chapter 8, not including > other information that is required by the > protocol. A Setup packet is always eight bytes. A control pipe > (including the Default Control Pipe) always > uses its wMaxPacketSize value for data payloads. > (Item 5.5.3 Control Transfer Packet Size Constraints). > > Using a value higher than 64 may cause troubles with some USB devices > (hubs, USB adapters, etc).
Okay, fine by me. I was basically just copying what the Windows driver was doing here, but I've tested with smaller sizes as well and if my memory serves me well that also worked. As I hinted at in the commit message this was mostly for performance improvement. Thierry
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