Re: [[PATCH v2]] drm/ast: fixed reading monitor EDID not stable issue

On Wed, 31 Oct 2018 at 18:12, Y.C. Chen yacheng600221@gmail.com wrote:

From: "Y.C. Chen" yc_chen@aspeedtech.com

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@aspeedtech.com

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

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