Re: [PATCH V5 6/7] i2c: tegra: fix PIO rx/tx residual transfer check
From: Dmitry Osipenko
Date: Wed Jun 12 2019 - 10:35:00 EST
11.06.2019 13:51, Bitan Biswas ÐÐÑÐÑ:
> Fix expression for residual bytes(less than word) transfer
> in I2C PIO mode RX/TX.
> Signed-off-by: Bitan Biswas <bbiswas@xxxxxxxxxx>
> - * Update state before writing to FIFO. If this casues us
> + * Update state before writing to FIFO. If this causes us
> * to finish writing all bytes (AKA buf_remaining goes to 0) we
> * have a potential for an interrupt (PACKET_XFER_COMPLETE is
> - * not maskable). We need to make sure that the isr sees
> - * buf_remaining as 0 and doesn't call us back re-entrantly.
> + * not maskable).
> buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
Looks like the comment could be removed altogether because it doesn't
make sense since interrupt handler is under xfer_lock which is kept
locked during of tegra_i2c_xfer_msg().
Moreover the comment says that "PACKET_XFER_COMPLETE is not maskable",
but then what I2C_INT_PACKET_XFER_COMPLETE masking does?