Hi Dave,
Thanks for your feedback. No issue found actually if I remove "volatile" on my platform. In my experience, if the value is volatile, adding "volatile" will be safer and no harm, that is why I add it by default. If you think it is not necessary, it's ok for me to remove it.
Regards,
Y.C. Chen
Dave Airlie <airlied@xxxxxxxxx> 於 2018年11月22日 週四 上午9:15寫道：
On Wed, 31 Oct 2018 at 18:12, Y.C. Chen <yacheng600221@xxxxxxxxx> wrote:
>
> From: "Y.C. Chen" <yc_chen@xxxxxxxxxxxxxx>
>
> v1: over-sample data to increase the stability with some specific monitors
> v2: refine to avoid infinite loop
This contains at least 4 whitespace breakages (val =) in a few
places, also why the volatiles, I don't think they make much sense
here, have you verified they are required?
Dave.
>
> Signed-off-by: Y.C. Chen <yc_chen@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/ast/ast_mode.c | 34 ++++++++++++++++++++++++++++------
> 1 file changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
> index 5e77d45..092e9a7 100644
> --- a/drivers/gpu/drm/ast/ast_mode.c
> +++ b/drivers/gpu/drm/ast/ast_mode.c
> @@ -972,9 +972,20 @@ static int get_clock(void *i2c_priv)
> {
> struct ast_i2c_chan *i2c = i2c_priv;
> struct ast_private *ast = i2c->dev->dev_private;
> - uint32_t val;
> + volatile uint32_t val, val2, count, pass;
> +
> + count = 0;
> + pass = 0;
> + val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01;
> + do {
> + val2 = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01;
> + if (val == val2) pass++;
> + else {
> + pass = 0;
> + val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4) & 0x01;
> + }
> + } while ((pass < 5) && (count++ < 0x10000));
>
> - val = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x10) >> 4;
> return val & 1 ? 1 : 0;
> }
>
> @@ -982,9 +993,20 @@ static int get_data(void *i2c_priv)
> {
> struct ast_i2c_chan *i2c = i2c_priv;
> struct ast_private *ast = i2c->dev->dev_private;
> - uint32_t val;
> + volatile uint32_t val, val2, count, pass;
> +
> + count = 0;
> + pass = 0;
> + val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01;
> + do {
> + val2 = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01;
> + if (val == val2) pass++;
> + else {
> + pass = 0;
> + val = (ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5) & 0x01;
> + }
> + } while ((pass < 5) && (count++ < 0x10000));
>
> - val = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x20) >> 5;
> return val & 1 ? 1 : 0;
> }
>
> @@ -997,7 +1019,7 @@ static void set_clock(void *i2c_priv, int clock)
>
> for (i = 0; i < 0x10000; i++) {
> ujcrb7 = ((clock & 0x01) ? 0 : 1);
> - ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xfe, ujcrb7);
> + ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf4, ujcrb7);
> jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x01);
> if (ujcrb7 == jtemp)
> break;
> @@ -1013,7 +1035,7 @@ static void set_data(void *i2c_priv, int data)
>
> for (i = 0; i < 0x10000; i++) {
> ujcrb7 = ((data & 0x01) ? 0 : 1) << 2;
> - ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xfb, ujcrb7);
> + ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0xf1, ujcrb7);
> jtemp = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xb7, 0x04);
> if (ujcrb7 == jtemp)
> break;
> --
> 1.8.3.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
_______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
