Hi,
On 07/20/2012 03:51 PM, Manjunathappa, Prakash wrote:
> Wait for active frame transfer to complete before disabling LCDC.
> At the same this wait is not be required when there are sync and
> underflow errors.
>
> Signed-off-by: Manjunathappa, Prakash <prakash.pm@xxxxxx>
> ---
> drivers/video/da8xx-fb.c | 58 ++++++++++++++++++++++++++++++++++++---------
> 1 files changed, 46 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
> index 4440292..c178592 100644
> --- a/drivers/video/da8xx-fb.c
> +++ b/drivers/video/da8xx-fb.c
> @@ -31,6 +31,7 @@
> #include <linux/cpufreq.h>
> #include <linux/console.h>
> #include <linux/slab.h>
> +#include <linux/delay.h>
> #include <video/da8xx-fb.h>
> #include <asm/div64.h>
>
> @@ -45,6 +46,7 @@
> #define LCD_PL_LOAD_DONE BIT(6)
> #define LCD_FIFO_UNDERFLOW BIT(5)
> #define LCD_SYNC_LOST BIT(2)
> +#define LCD_FRAME_DONE BIT(0)
>
> /* LCD DMA Control Register */
> #define LCD_DMA_BURST_SIZE(x) ((x) << 4)
> @@ -129,6 +131,8 @@
> #define RIGHT_MARGIN 64
> #define UPPER_MARGIN 32
> #define LOWER_MARGIN 32
> +#define WAIT_FOR_FRAME_DONE true
> +#define NO_WAIT_FOR_FRAME_DONE false
These defines look a bit strange. While I consider it acceptable, one
really should know the arguments of a function and hence it doesn't make
sense to add an extra abstraction to bool (in contrast to flags where
such defines are really helpful).
>
> static resource_size_t da8xx_fb_reg_base;
> static struct resource *lcdc_regs;
> @@ -280,13 +284,39 @@ static inline void lcd_enable_raster(void)
> }
>
> /* Disable the Raster Engine of the LCD Controller */
> -static inline void lcd_disable_raster(void)
> +static inline void lcd_disable_raster(bool wait_for_frame_done)
> {
> u32 reg;
> + u32 loop_cnt = 0;
> + u32 stat;
> + u32 i = 0;
> +
> + /* 50 milli seconds should be sufficient for a frame to complete */
> + if (wait_for_frame_done)
> + loop_cnt = 50;
>
> reg = lcdc_read(LCD_RASTER_CTRL_REG);
> if (reg & LCD_RASTER_ENABLE)
> lcdc_write(reg & ~LCD_RASTER_ENABLE, LCD_RASTER_CTRL_REG);
> +
> + /* Wait for the current frame to complete */
> + do {
> + if (lcd_revision == LCD_VERSION_1)
> + stat = lcdc_read(LCD_STAT_REG);
> + else
> + stat = lcdc_read(LCD_RAW_STAT_REG);
> + mdelay(1);
> + } while (!(stat & LCD_FRAME_DONE) && (i++ < loop_cnt));
I don't know the documentation of your hardware but this really looks
like you are waiting after you disabled it.
> +
> + if (lcd_revision == LCD_VERSION_1)
> + lcdc_write(stat, LCD_STAT_REG);
> + else
> + lcdc_write(stat, LCD_MASKED_STAT_REG);
> +
> + if ((loop_cnt != 0) && (i >= loop_cnt)) {
> + pr_err("LCD Controller timed out\n");
> + return;
> + }
> }
>
> static void lcd_blit(int load_mode, struct da8xx_fb_par *par)
> @@ -663,7 +693,7 @@ static int fb_setcolreg(unsigned regno, unsigned red, unsigned green,
> static void lcd_reset(struct da8xx_fb_par *par)
> {
> /* Disable the Raster if previously Enabled */
> - lcd_disable_raster();
> + lcd_disable_raster(NO_WAIT_FOR_FRAME_DONE);
>
> /* DMA has to be disabled */
> lcdc_write(0, LCD_DMA_CTRL_REG);
> @@ -760,7 +790,8 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
> u32 reg_int;
>
> if ((stat & LCD_SYNC_LOST) && (stat & LCD_FIFO_UNDERFLOW)) {
> - lcd_disable_raster();
> + pr_err("LCDC sync lost or underflow error occured\n");
> + lcd_disable_raster(NO_WAIT_FOR_FRAME_DONE);
> lcdc_write(stat, LCD_MASKED_STAT_REG);
> lcd_enable_raster();
> } else if (stat & LCD_PL_LOAD_DONE) {
> @@ -770,7 +801,7 @@ static irqreturn_t lcdc_irq_handler_rev02(int irq, void *arg)
> * interrupt via the following write to the status register. If
> * this is done after then one gets multiple PL done interrupts.
> */
> - lcd_disable_raster();
> + lcd_disable_raster(NO_WAIT_FOR_FRAME_DONE);
>
> lcdc_write(stat, LCD_MASKED_STAT_REG);
>
> @@ -815,7 +846,8 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
> u32 reg_ras;
>
> if ((stat & LCD_SYNC_LOST) && (stat & LCD_FIFO_UNDERFLOW)) {
> - lcd_disable_raster();
> + pr_err("LCDC sync lost or underflow error occured\n");
> + lcd_disable_raster(NO_WAIT_FOR_FRAME_DONE);
> lcdc_write(stat, LCD_STAT_REG);
> lcd_enable_raster();
> } else if (stat & LCD_PL_LOAD_DONE) {
> @@ -825,7 +857,7 @@ static irqreturn_t lcdc_irq_handler_rev01(int irq, void *arg)
> * interrupt via the following write to the status register. If
> * this is done after then one gets multiple PL done interrupts.
> */
> - lcd_disable_raster();
> + lcd_disable_raster(NO_WAIT_FOR_FRAME_DONE);
>
> lcdc_write(stat, LCD_STAT_REG);
>
> @@ -945,7 +977,7 @@ static int lcd_da8xx_cpufreq_transition(struct notifier_block *nb,
> if (val == CPUFREQ_POSTCHANGE) {
> if (par->lcd_fck_rate != clk_get_rate(par->lcdc_clk)) {
> par->lcd_fck_rate = clk_get_rate(par->lcdc_clk);
> - lcd_disable_raster();
> + lcd_disable_raster(WAIT_FOR_FRAME_DONE);
> lcd_calc_clk_divider(par);
> lcd_enable_raster();
> }
> @@ -982,7 +1014,7 @@ static int __devexit fb_remove(struct platform_device *dev)
> if (par->panel_power_ctrl)
> par->panel_power_ctrl(0);
>
> - lcd_disable_raster();
> + lcd_disable_raster(WAIT_FOR_FRAME_DONE);
> lcdc_write(0, LCD_RASTER_CTRL_REG);
>
> /* disable DMA */
> @@ -1095,7 +1127,7 @@ static int cfb_blank(int blank, struct fb_info *info)
> if (par->panel_power_ctrl)
> par->panel_power_ctrl(0);
>
> - lcd_disable_raster();
> + lcd_disable_raster(WAIT_FOR_FRAME_DONE);
> break;
> default:
> ret = -EINVAL;
> @@ -1435,7 +1467,7 @@ static int fb_suspend(struct platform_device *dev, pm_message_t state)
> par->panel_power_ctrl(0);
>
> fb_set_suspend(info, 1);
> - lcd_disable_raster();
> + lcd_disable_raster(WAIT_FOR_FRAME_DONE);
> clk_disable(par->lcdc_clk);
> console_unlock();
>
> @@ -1447,11 +1479,13 @@ static int fb_resume(struct platform_device *dev)
> struct da8xx_fb_par *par = info->par;
>
> console_lock();
> - if (par->panel_power_ctrl)
> - par->panel_power_ctrl(1);
>
> clk_enable(par->lcdc_clk);
> + usleep_range(1000, 2000);
> lcd_enable_raster();
> + if (par->panel_power_ctrl)
> + par->panel_power_ctrl(1);
> +
This change looks unrelated and should go in a separate patch?
> fb_set_suspend(info, 0);
> console_unlock();
>
Best regards,
Florian Tobias Schandinat
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