On 04/25/2016 08:51 AM, Jarkko Nikula wrote:
[ ... ]
@@ -413,8 +416,16 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
struct i2c_msg *msgs = dev->msgs;
u32 ic_con, ic_tar = 0;
- /* Disable the adapter */
- __i2c_dw_enable(dev, false);
+ if (dev->enabled) {
+ u32 ic_status;
+
+ /* check ic_tar and ic_con can be dynamically updated */
+ ic_status = dw_readl(dev, DW_IC_STATUS);
+ if (ic_status & DW_IC_STATUS_ACTIVITY
+ || !(ic_status & DW_IC_STATUS_TX_EMPTY)) {
+ __i2c_dw_enable(dev, false);
+ }
+ }
Worth to double check this. I see bit 1 means TX FIFO not full and bit 2
is TX FIFO completely empty.
the conditions to be able to update IC_TAR dynamically are:
- Adapter isn't doing any TX/RX operation (IC_STATUS[5] == 0) and
- There are no entries in TX FIFO (IC_STATUS[2] == 1)
So... yeah, the condition above seems wrong. I should be reading bit 5,
not bit 1. Thanks! However:
IC_STATUS[5] signals activity for master mode
IC_STATUS[6] signals activity for slave mode
IC_STATUS[0] is IC_STATUS[5]|IC_STATUS[6]
And this controller is never in slave mode, only master mode, so it
should be equivalent.
I wonder if I even have to check bit 5 since AFAICS we wouldn't be able
to even call this function if there were any operation on tx/rx.
Otherwise I'm fine with the patch as long as it works for Christian.
Anyway, I'll re-test with bit 5 checked and send an update.
Lucas De Marchi
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