Messages in this thread | | | Date | Fri, 30 Oct 2015 14:03:53 +0200 | From | Jarkko Nikula <> | Subject | Re: [PATCH] i2c: designware: Don't mask TX_EMPTY if write is in progress |
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Hi
On 10/30/2015 09:37 AM, Jisheng Zhang wrote: > Currently when i2c_msg index search is completed, TX_EMPTY interrupt > will be masked. But if the size of i2c_msg data is longer than the size > of the tx buffer, we still need TX_EMPTY interrupt, otherwise we will > get "controller timed out" error. > > This patch fixes this issue by only masking TX_EMPTY if i2c_msg index > search is completed and write is not in progress. > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > --- > drivers/i2c/busses/i2c-designware-core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c > index 7441cdc..a2eb212 100644 > --- a/drivers/i2c/busses/i2c-designware-core.c > +++ b/drivers/i2c/busses/i2c-designware-core.c > @@ -542,10 +542,11 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) > } > > /* > - * If i2c_msg index search is completed, we don't need TX_EMPTY > - * interrupt any more. > + * If i2c_msg index search is completed and writing is not in progress, > + * we don't need TX_EMPTY interrupt any more. > */ > - if (dev->msg_write_idx == dev->msgs_num) > + if (dev->msg_write_idx == dev->msgs_num && > + !(dev->status & STATUS_WRITE_IN_PROGRESS)) > intr_mask &= ~DW_IC_INTR_TX_EMPTY; > This looks a possible scenario here. What I'm wondering how is the transfer ending and what condition in i2c_dw_isr() causes the complete() call?
Assuming we break the for loop in i2c_dw_xfer_msg() with buf_len > 0 and dev->msg_write_idx == dev->msgs_num how we get back inside the for loop for writing the remaining bytes and stop command?
-- Jarkko
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