Re: [PATCH v3 04/24] drm/rockchip: dw-mipi-dsi: fix command header writes

Sean Paul
2017-01-30T15:43:06Z

On Sun, Jan 29, 2017 at 01:24:24PM +0000, John Keeping wrote:
> In a couple of places here we use "val" for the value that is about to
> be written to a register but then reuse the same variable for the value
> of a status register before we get around to writing it. Rename the
> value to be written to so that we write the value we intend to and not
> what we have just read from the status register.
>

Oh my.

Reviewed-by: Sean Paul <seanpaul@chromium.org>

> Signed-off-by: John Keeping <john@metanate.com>
> Tested-by: Chris Zhong <zyw@rock-chips.com>
> Reviewed-by: Chris Zhong <zyw@rock-chips.com>
> ---
> Unchanged in v3
> Unchanged in v2
>
> drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> index bd92e58b64f3..4cbbbcb619b7 100644
> --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
> @@ -542,9 +542,10 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
> return 0;
> }
>
> -static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 val)
> +static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
> {
> int ret;
> + u32 val;
>
> ret = readx_poll_timeout(readl, dsi->base + DSI_CMD_PKT_STATUS,
> val, !(val & GEN_CMD_FULL), 1000,
> @@ -554,7 +555,7 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 val)
> return ret;
> }
>
> - dsi_write(dsi, DSI_GEN_HDR, val);
> + dsi_write(dsi, DSI_GEN_HDR, hdr_val);
>
> ret = readx_poll_timeout(readl, dsi->base + DSI_CMD_PKT_STATUS,
> val, val & (GEN_CMD_EMPTY | GEN_PLD_W_EMPTY),
> @@ -587,8 +588,9 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
> {
> const u32 *tx_buf = msg->tx_buf;
> int len = msg->tx_len, pld_data_bytes = sizeof(*tx_buf), ret;
> - u32 val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type);
> + u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type);
> u32 remainder = 0;
> + u32 val;
>
> if (msg->tx_len < 3) {
> dev_err(dsi->dev, "wrong tx buf length %zu for long write\n",
> @@ -617,7 +619,7 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
> }
> }
>
> - return dw_mipi_dsi_gen_pkt_hdr_write(dsi, val);
> + return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val);
> }
>
> static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
> --
> 2.11.0.197.gb556de5.dirty
>
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--
Sean Paul, Software Engineer, Google / Chromium OS