2022-06-10 22:54:50

by Luca Weiss

Subject: [PATCH] drm/msm/dsi: Use single function for reset

From: Vladimir Lypak <[email protected]>

There is currently two function for performing reset: dsi_sw_reset and
dsi_sw_reset_restore. Only difference betwean those is that latter one
assumes that DSI controller is enabled. In contrary former one assumes
that controller is disabled and executed during power-on. However this
assumtion is not true mobile devices which have boot splash set up by
boot-loader.

This patch removes dsi_sw_reset_restore and makes dsi_sw_reset disable
DSI controller during reset sequence if it's enabled.

Signed-off-by: Vladimir Lypak <[email protected]>
Signed-off-by: Luca Weiss <[email protected]>
---
drivers/gpu/drm/msm/dsi/dsi_host.c | 48 +++++++++++++-----------------
1 file changed, 21 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index a95d5df52653..bab2634ebd11 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1080,12 +1080,32 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)

static void dsi_sw_reset(struct msm_dsi_host *msm_host)
{
+ u32 ctrl;
+
+ ctrl = dsi_read(msm_host, REG_DSI_CTRL);
+
+ if (ctrl & DSI_CTRL_ENABLE) {
+ dsi_write(msm_host, REG_DSI_CTRL, ctrl & ~DSI_CTRL_ENABLE);
+ /*
+ * dsi controller need to be disabled before
+ * clocks turned on
+ */
+ wmb();
+ }
+
dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
wmb(); /* clocks need to be enabled before reset */

+ /* dsi controller can only be reset while clocks are running */
dsi_write(msm_host, REG_DSI_RESET, 1);
msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
dsi_write(msm_host, REG_DSI_RESET, 0);
+ wmb(); /* controller out of reset */
+
+ if (ctrl & DSI_CTRL_ENABLE) {
+ dsi_write(msm_host, REG_DSI_CTRL, ctrl);
+ wmb(); /* make sure dsi controller enabled again */
+ }
}

static void dsi_op_mode_config(struct msm_dsi_host *msm_host,
@@ -1478,32 +1498,6 @@ static int dsi_cmds2buf_tx(struct msm_dsi_host *msm_host,
return len;
}

-static void dsi_sw_reset_restore(struct msm_dsi_host *msm_host)
-{
- u32 data0, data1;
-
- data0 = dsi_read(msm_host, REG_DSI_CTRL);
- data1 = data0;
- data1 &= ~DSI_CTRL_ENABLE;
- dsi_write(msm_host, REG_DSI_CTRL, data1);
- /*
- * dsi controller need to be disabled before
- * clocks turned on
- */
- wmb();
-
- dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
- wmb(); /* make sure clocks enabled */
-
- /* dsi controller can only be reset while clocks are running */
- dsi_write(msm_host, REG_DSI_RESET, 1);
- msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
- dsi_write(msm_host, REG_DSI_RESET, 0);
- wmb(); /* controller out of reset */
- dsi_write(msm_host, REG_DSI_CTRL, data0);
- wmb(); /* make sure dsi controller enabled again */
-}
-
static void dsi_hpd_worker(struct work_struct *work)
{
struct msm_dsi_host *msm_host =
@@ -1520,7 +1514,7 @@ static void dsi_err_worker(struct work_struct *work)

pr_err_ratelimited("%s: status=%x\n", __func__, status);
if (status & DSI_ERR_STATE_MDP_FIFO_UNDERFLOW)
- dsi_sw_reset_restore(msm_host);
+ dsi_sw_reset(msm_host);

/* It is safe to clear here because error irq is disabled. */
msm_host->err_work_state = 0;
--
2.36.1

2022-06-11 00:08:56

by Abhinav Kumar

Subject: Re: [PATCH] drm/msm/dsi: Use single function for reset

On 6/10/2022 3:02 PM, Luca Weiss wrote:
> From: Vladimir Lypak <[email protected]>
>
> There is currently two function for performing reset: dsi_sw_reset and
> dsi_sw_reset_restore. Only difference betwean those is that latter one
betwean --> between
> assumes that DSI controller is enabled. In contrary former one assumes
> that controller is disabled and executed during power-on. However this
> assumtion is not true mobile devices which have boot splash set up by
> boot-loader.
>
> This patch removes dsi_sw_reset_restore and makes dsi_sw_reset disable
> DSI controller during reset sequence if it's enabled.
>
> Signed-off-by: Vladimir Lypak <[email protected]>
> Signed-off-by: Luca Weiss <[email protected]>

Otherwise, looks good to me,

Reviewed-by: Abhinav Kumar <[email protected]>
> ---
> drivers/gpu/drm/msm/dsi/dsi_host.c | 48 +++++++++++++-----------------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index a95d5df52653..bab2634ebd11 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1080,12 +1080,32 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>
> static void dsi_sw_reset(struct msm_dsi_host *msm_host)
> {
> + u32 ctrl;
> +
> + ctrl = dsi_read(msm_host, REG_DSI_CTRL);
> +
> + if (ctrl & DSI_CTRL_ENABLE) {
> + dsi_write(msm_host, REG_DSI_CTRL, ctrl & ~DSI_CTRL_ENABLE);
> + /*
> + * dsi controller need to be disabled before
> + * clocks turned on
> + */
> + wmb();
> + }
> +
> dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
> wmb(); /* clocks need to be enabled before reset */
>
> + /* dsi controller can only be reset while clocks are running */
> dsi_write(msm_host, REG_DSI_RESET, 1);
> msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
> dsi_write(msm_host, REG_DSI_RESET, 0);
> + wmb(); /* controller out of reset */
> +
> + if (ctrl & DSI_CTRL_ENABLE) {
> + dsi_write(msm_host, REG_DSI_CTRL, ctrl);
> + wmb(); /* make sure dsi controller enabled again */
> + }
> }
>
> static void dsi_op_mode_config(struct msm_dsi_host *msm_host,
> @@ -1478,32 +1498,6 @@ static int dsi_cmds2buf_tx(struct msm_dsi_host *msm_host,
> return len;
> }
>
> -static void dsi_sw_reset_restore(struct msm_dsi_host *msm_host)
> -{
> - u32 data0, data1;
> -
> - data0 = dsi_read(msm_host, REG_DSI_CTRL);
> - data1 = data0;
> - data1 &= ~DSI_CTRL_ENABLE;
> - dsi_write(msm_host, REG_DSI_CTRL, data1);
> - /*
> - * dsi controller need to be disabled before
> - * clocks turned on
> - */
> - wmb();
> -
> - dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
> - wmb(); /* make sure clocks enabled */
> -
> - /* dsi controller can only be reset while clocks are running */
> - dsi_write(msm_host, REG_DSI_RESET, 1);
> - msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
> - dsi_write(msm_host, REG_DSI_RESET, 0);
> - wmb(); /* controller out of reset */
> - dsi_write(msm_host, REG_DSI_CTRL, data0);
> - wmb(); /* make sure dsi controller enabled again */
> -}
> -
> static void dsi_hpd_worker(struct work_struct *work)
> {
> struct msm_dsi_host *msm_host =
> @@ -1520,7 +1514,7 @@ static void dsi_err_worker(struct work_struct *work)
>
> pr_err_ratelimited("%s: status=%x\n", __func__, status);
> if (status & DSI_ERR_STATE_MDP_FIFO_UNDERFLOW)
> - dsi_sw_reset_restore(msm_host);
> + dsi_sw_reset(msm_host);
>
> /* It is safe to clear here because error irq is disabled. */
> msm_host->err_work_state = 0;

2022-06-15 13:17:34

by Dmitry Baryshkov

Subject: Re: [PATCH] drm/msm/dsi: Use single function for reset

On 11/06/2022 01:02, Luca Weiss wrote:
> From: Vladimir Lypak <[email protected]>
>
> There is currently two function for performing reset: dsi_sw_reset and
> dsi_sw_reset_restore. Only difference betwean those is that latter one
> assumes that DSI controller is enabled. In contrary former one assumes
> that controller is disabled and executed during power-on. However this
> assumtion is not true mobile devices which have boot splash set up by
> boot-loader.
>
> This patch removes dsi_sw_reset_restore and makes dsi_sw_reset disable
> DSI controller during reset sequence if it's enabled.
>
> Signed-off-by: Vladimir Lypak <[email protected]>
> Signed-off-by: Luca Weiss <[email protected]>

Reviewed-by: Dmitry Baryshkov <[email protected]>

> ---
> drivers/gpu/drm/msm/dsi/dsi_host.c | 48 +++++++++++++-----------------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index a95d5df52653..bab2634ebd11 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -1080,12 +1080,32 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>
> static void dsi_sw_reset(struct msm_dsi_host *msm_host)
> {
> + u32 ctrl;
> +
> + ctrl = dsi_read(msm_host, REG_DSI_CTRL);
> +
> + if (ctrl & DSI_CTRL_ENABLE) {
> + dsi_write(msm_host, REG_DSI_CTRL, ctrl & ~DSI_CTRL_ENABLE);
> + /*
> + * dsi controller need to be disabled before
> + * clocks turned on
> + */
> + wmb();
> + }
> +
> dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
> wmb(); /* clocks need to be enabled before reset */
>
> + /* dsi controller can only be reset while clocks are running */
> dsi_write(msm_host, REG_DSI_RESET, 1);
> msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
> dsi_write(msm_host, REG_DSI_RESET, 0);
> + wmb(); /* controller out of reset */
> +
> + if (ctrl & DSI_CTRL_ENABLE) {
> + dsi_write(msm_host, REG_DSI_CTRL, ctrl);
> + wmb(); /* make sure dsi controller enabled again */
> + }
> }
>
> static void dsi_op_mode_config(struct msm_dsi_host *msm_host,
> @@ -1478,32 +1498,6 @@ static int dsi_cmds2buf_tx(struct msm_dsi_host *msm_host,
> return len;
> }
>
> -static void dsi_sw_reset_restore(struct msm_dsi_host *msm_host)
> -{
> - u32 data0, data1;
> -
> - data0 = dsi_read(msm_host, REG_DSI_CTRL);
> - data1 = data0;
> - data1 &= ~DSI_CTRL_ENABLE;
> - dsi_write(msm_host, REG_DSI_CTRL, data1);
> - /*
> - * dsi controller need to be disabled before
> - * clocks turned on
> - */
> - wmb();
> -
> - dsi_write(msm_host, REG_DSI_CLK_CTRL, DSI_CLK_CTRL_ENABLE_CLKS);
> - wmb(); /* make sure clocks enabled */
> -
> - /* dsi controller can only be reset while clocks are running */
> - dsi_write(msm_host, REG_DSI_RESET, 1);
> - msleep(DSI_RESET_TOGGLE_DELAY_MS); /* make sure reset happen */
> - dsi_write(msm_host, REG_DSI_RESET, 0);
> - wmb(); /* controller out of reset */
> - dsi_write(msm_host, REG_DSI_CTRL, data0);
> - wmb(); /* make sure dsi controller enabled again */
> -}
> -
> static void dsi_hpd_worker(struct work_struct *work)
> {
> struct msm_dsi_host *msm_host =
> @@ -1520,7 +1514,7 @@ static void dsi_err_worker(struct work_struct *work)
>
> pr_err_ratelimited("%s: status=%x\n", __func__, status);
> if (status & DSI_ERR_STATE_MDP_FIFO_UNDERFLOW)
> - dsi_sw_reset_restore(msm_host);
> + dsi_sw_reset(msm_host);
>
> /* It is safe to clear here because error irq is disabled. */
> msm_host->err_work_state = 0;


--
With best wishes
Dmitry