Hi Florian Tobias Schandinat,
On Sun, Jul 22, 2012 at 17:20:28, Florian Tobias Schandinat wrote:
> 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).
>
I agree to remove them.
> >
> > 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.
>
Correct, it is expected to wait for frame_done before applying the software reset.
I will re-write the commit message to convey the same.
> > +
> > + 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?
>
Agree, I will send out in separate patch.
Thanks,
Prakash
> > fb_set_suspend(info, 0);
> > console_unlock();
> >
>
>
> Best regards,
>
> Florian Tobias Schandinat
>
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