| Message ID | 20180920180323.217377-3-swboyd@chromium.org |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Fix qcom geni i2c DMA handling | expand |
Hi, On Thu, Sep 20, 2018 at 11:03 AM Stephen Boyd <swboyd@chromium.org> wrote: > > We never really look at the 'ret' local variable in these functions, so > let's remove it to make way for shorter and simpler code. Furthermore, > we can shorten some lines by adding two local variables for the SE and > the message length so that everything fits in 80 columns. And kernel > style is to leave the return statement by itself, detached from the rest > of the function. > > Cc: Karthikeyan Ramasubramanian <kramasub@codeaurora.org> > Cc: Sagar Dharia <sdharia@codeaurora.org> > Cc: Girish Mahadevan <girishm@codeaurora.org> > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > --- > drivers/i2c/busses/i2c-qcom-geni.c | 54 ++++++++++++++---------------- > 1 file changed, 25 insertions(+), 29 deletions(-) I didn't hate the old code, but you're right that this looks a little better. Reviewed-by: Douglas Anderson <dianders@chromium.org> NOTE: now that you're cleaning it up, I'd personally go even further and totally get rid of the "mode" local variable. Basically, just: dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); if (dma_buf) geni_se_select_mode(se, GENI_SE_DMA); else geni_se_select_mode(se, GENI_SE_FIFO); ...elsewhere just continue to use "dma_buf" being NULL to mean FIFO if you have to fall back to the FIFO case you set dma_buf to NULL after calling i2c_put_dma_safe_msg_buf() to indicate to later code that you're in FIFO mode. I prototyped this up and the net-net is one fewer line of code and also the nice consistency that you never hold dma_buf in a pointer after you've freed it. -Doug
Quoting Doug Anderson (2018-09-20 13:22:37) > Hi, > On Thu, Sep 20, 2018 at 11:03 AM Stephen Boyd <swboyd@chromium.org> wrote: > > > > We never really look at the 'ret' local variable in these functions, so > > let's remove it to make way for shorter and simpler code. Furthermore, > > we can shorten some lines by adding two local variables for the SE and > > the message length so that everything fits in 80 columns. And kernel > > style is to leave the return statement by itself, detached from the rest > > of the function. > > > > Cc: Karthikeyan Ramasubramanian <kramasub@codeaurora.org> > > Cc: Sagar Dharia <sdharia@codeaurora.org> > > Cc: Girish Mahadevan <girishm@codeaurora.org> > > Signed-off-by: Stephen Boyd <swboyd@chromium.org> > > --- > > drivers/i2c/busses/i2c-qcom-geni.c | 54 ++++++++++++++---------------- > > 1 file changed, 25 insertions(+), 29 deletions(-) > > I didn't hate the old code, but you're right that this looks a little better. > > Reviewed-by: Douglas Anderson <dianders@chromium.org> > > NOTE: now that you're cleaning it up, I'd personally go even further > and totally get rid of the "mode" local variable. Basically, just: > > dma_buf = i2c_get_dma_safe_msg_buf(msg, 32); > if (dma_buf) > geni_se_select_mode(se, GENI_SE_DMA); > else > geni_se_select_mode(se, GENI_SE_FIFO); Sure that's fine. I'll resend this one patch with that squashed in.
> Sure that's fine. I'll resend this one patch with that squashed in.
Waiting for this resend.
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 9f2eb02481d3..1215bb21c9f1 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -368,6 +368,8 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, enum geni_se_xfer_mode mode; unsigned long time_left = XFER_TIMEOUT; void *dma_buf; + struct geni_se *se = &gi2c->se; + size_t len = msg->len; gi2c->cur = msg; mode = GENI_SE_FIFO; @@ -375,19 +377,14 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (dma_buf) mode = GENI_SE_DMA; - geni_se_select_mode(&gi2c->se, mode); - writel_relaxed(msg->len, gi2c->se.base + SE_I2C_RX_TRANS_LEN); - geni_se_setup_m_cmd(&gi2c->se, I2C_READ, m_param); - if (mode == GENI_SE_DMA) { - int ret; - - ret = geni_se_rx_dma_prep(&gi2c->se, dma_buf, msg->len, - &rx_dma); - if (ret) { - mode = GENI_SE_FIFO; - geni_se_select_mode(&gi2c->se, mode); - i2c_put_dma_safe_msg_buf(dma_buf, msg, false); - } + geni_se_select_mode(se, mode); + writel_relaxed(len, se->base + SE_I2C_RX_TRANS_LEN); + geni_se_setup_m_cmd(se, I2C_READ, m_param); + + if (dma_buf && geni_se_rx_dma_prep(se, dma_buf, len, &rx_dma)) { + mode = GENI_SE_FIFO; + geni_se_select_mode(se, mode); + i2c_put_dma_safe_msg_buf(dma_buf, msg, false); } time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT); @@ -398,9 +395,10 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (mode == GENI_SE_DMA) { if (gi2c->err) geni_i2c_rx_fsm_rst(gi2c); - geni_se_rx_dma_unprep(&gi2c->se, rx_dma, msg->len); + geni_se_rx_dma_unprep(se, rx_dma, len); i2c_put_dma_safe_msg_buf(dma_buf, msg, !gi2c->err); } + return gi2c->err; } @@ -411,6 +409,8 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, enum geni_se_xfer_mode mode; unsigned long time_left; void *dma_buf; + struct geni_se *se = &gi2c->se; + size_t len = msg->len; gi2c->cur = msg; mode = GENI_SE_FIFO; @@ -418,23 +418,18 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (dma_buf) mode = GENI_SE_DMA; - geni_se_select_mode(&gi2c->se, mode); - writel_relaxed(msg->len, gi2c->se.base + SE_I2C_TX_TRANS_LEN); - geni_se_setup_m_cmd(&gi2c->se, I2C_WRITE, m_param); - if (mode == GENI_SE_DMA) { - int ret; - - ret = geni_se_tx_dma_prep(&gi2c->se, dma_buf, msg->len, - &tx_dma); - if (ret) { - mode = GENI_SE_FIFO; - geni_se_select_mode(&gi2c->se, mode); - i2c_put_dma_safe_msg_buf(dma_buf, msg, false); - } + geni_se_select_mode(se, mode); + writel_relaxed(len, se->base + SE_I2C_TX_TRANS_LEN); + geni_se_setup_m_cmd(se, I2C_WRITE, m_param); + + if (dma_buf && geni_se_tx_dma_prep(se, dma_buf, len, &tx_dma)) { + mode = GENI_SE_FIFO; + geni_se_select_mode(se, mode); + i2c_put_dma_safe_msg_buf(dma_buf, msg, false); } if (mode == GENI_SE_FIFO) /* Get FIFO IRQ */ - writel_relaxed(1, gi2c->se.base + SE_GENI_TX_WATERMARK_REG); + writel_relaxed(1, se->base + SE_GENI_TX_WATERMARK_REG); time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT); if (!time_left) @@ -444,9 +439,10 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (mode == GENI_SE_DMA) { if (gi2c->err) geni_i2c_tx_fsm_rst(gi2c); - geni_se_tx_dma_unprep(&gi2c->se, tx_dma, msg->len); + geni_se_tx_dma_unprep(se, tx_dma, len); i2c_put_dma_safe_msg_buf(dma_buf, msg, !gi2c->err); } + return gi2c->err; }
We never really look at the 'ret' local variable in these functions, so let's remove it to make way for shorter and simpler code. Furthermore, we can shorten some lines by adding two local variables for the SE and the message length so that everything fits in 80 columns. And kernel style is to leave the return statement by itself, detached from the rest of the function. Cc: Karthikeyan Ramasubramanian <kramasub@codeaurora.org> Cc: Sagar Dharia <sdharia@codeaurora.org> Cc: Girish Mahadevan <girishm@codeaurora.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> --- drivers/i2c/busses/i2c-qcom-geni.c | 54 ++++++++++++++---------------- 1 file changed, 25 insertions(+), 29 deletions(-)