Re: [PATCH] drm/bridge/synopsys: dsi: readl_poll_timeout return value clean up

Hi Andrzej,

On 03/02/2018 11:21 AM, Andrzej Hajda wrote:

On 01.03.2018 10:00, Philippe CORNU wrote:

...

Hi Archit, Andrzej & Laurent,

May I ask you please your feedback on this small patch? Many thanks,

Philippe :-)

On 02/04/2018 10:36 PM, Philippe Cornu wrote:

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The readl_poll_timeout() return value is 0 in case of success so it is better to detect errors without taking care of the return value sign.

Signed-off-by: Philippe Cornu philippe.cornu@st.com

The patch is of course correct. However I am not sure if necessary. For sure functionally it does not change anything. AFAIK kernel CodingStyle says nothing about it, so I suppose it is matter of personal taste.

I sent this tiny patch in order to homogenize the dw mipi driver because there were both cases "if (ret)" & "if (ret < 0)" in the source code.

I did not really find a preferred way in the kernel source code so I selected what sounds the best to me ie "if (ret)" but it is not a problem to make another patch for "if (ret < 0)" everywhere :-)

In any case, the most important from my pov is to have a homogeneous source code :-)

Does anyone have a preferred choice between "if (ret)" & "if (ret < 0)" after a "ret = readl_poll_timeout()"?

Anyway I can give it: Reviewed-by: Andrzej Hajda a.hajda@samsung.com

Many thanks, Philippe :)

-- Regards Andrzej

...

...

---

drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c index 65aeb3f78b48..4d0e8471a15c 100644 --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c @@ -342,7 +342,7 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) ret = qq(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_CMD_FULL), 1000, CMD_PKT_STATUS_TIMEOUT_US);

• if (ret < 0) {

• if (ret) { dev_err(dsi->dev, "failed to get available command FIFO\n"); return ret; }

@@ -353,7 +353,7 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val) ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, (val & mask) == mask, 1000, CMD_PKT_STATUS_TIMEOUT_US);

• if (ret < 0) {

• if (ret) { dev_err(dsi->dev, "failed to write command FIFO\n"); return ret; }

@@ -385,7 +385,7 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi, ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, val, !(val & GEN_PLD_W_FULL), 1000, CMD_PKT_STATUS_TIMEOUT_US);

• if (ret < 0) {
  

• if (ret) {
  	dev_err(dsi->dev,
  		"failed to get available write payload FIFO\n");
  	return ret;
  

@@ -716,13 +716,13 @@ static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)

ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val,
			 val & PHY_LOCK, 1000, PHY_STATUS_TIMEOUT_US);

• if (ret < 0)

• if (ret) DRM_DEBUG_DRIVER("failed to wait phy lock state\n");

  ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS, val, val & PHY_STOP_STATE_CLK_LANE, 1000, PHY_STATUS_TIMEOUT_US);

• if (ret < 0)

• if (ret) DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n"); }