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OMAP: DSS2: DISPC: Fix context save/restore

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The current method of saving and restoring the context could cause a
restore before saving, effectively "restoring" zero values to registers.

Add ctx_valid field to indicate if the saved context is valid and can be
restored.

Also restructure the code to save the ctx_loss_count in save_context(),
which makes more sense than the previous method of storing new
ctx_loss_count in dispc_need_ctx_restore.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This commit is contained in:
Tomi Valkeinen 2011-06-01 15:54:06 +03:00
parent 39020710e7
commit 49ea86f3fa
1 changed files with 38 additions and 59 deletions
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97
drivers/video/omap2/dss/dispc.c
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@ -114,6 +114,7 @@ static struct {
u32 error_irqs;
struct work_struct error_work;
bool ctx_valid;
u32 ctx[DISPC_SZ_REGS / sizeof(u32)];
#ifdef CONFIG_OMAP2_DSS_COLLECT_IRQ_STATS
@ -146,6 +147,23 @@ static inline u32 dispc_read_reg(const u16 idx)
return __raw_readl(dispc.base + idx);
}
static int dispc_get_ctx_loss_count(void)
{
struct device *dev = &dispc.pdev->dev;
struct omap_display_platform_data *pdata = dev->platform_data;
struct omap_dss_board_info *board_data = pdata->board_data;
int cnt;
if (!board_data->get_context_loss_count)
return -ENOENT;
cnt = board_data->get_context_loss_count(dev);
WARN_ONCE(cnt < 0, "get_context_loss_count failed: %d\n", cnt);
return cnt;
}
#define SR(reg) \
dispc.ctx[DISPC_##reg / sizeof(u32)] = dispc_read_reg(DISPC_##reg)
#define RR(reg) \
@ -322,14 +340,30 @@ static void dispc_save_context(void)
if (dss_has_feature(FEAT_CORE_CLK_DIV))
SR(DIVISOR);
dispc.ctx_loss_cnt = dispc_get_ctx_loss_count();
dispc.ctx_valid = true;
DSSDBG("context saved, ctx_loss_count %d\n", dispc.ctx_loss_cnt);
}
static void dispc_restore_context(void)
{
int i;
int i, ctx;
DSSDBG("dispc_restore_context\n");
if (!dispc.ctx_valid)
return;
ctx = dispc_get_ctx_loss_count();
if (ctx >= 0 && ctx == dispc.ctx_loss_cnt)
return;
DSSDBG("ctx_loss_count: saved %d, current %d\n",
dispc.ctx_loss_cnt, ctx);
/*RR(IRQENABLE);*/
/*RR(CONTROL);*/
RR(CONFIG);
@ -508,65 +542,13 @@ static void dispc_restore_context(void)
* the context is fully restored
*/
RR(IRQENABLE);
DSSDBG("context restored\n");
}
#undef SR
#undef RR
static void dispc_init_ctx_loss_count(void)
{
struct device *dev = &dispc.pdev->dev;
struct omap_display_platform_data *pdata = dev->platform_data;
struct omap_dss_board_info *board_data = pdata->board_data;
int cnt = 0;
/*
* get_context_loss_count returns negative on error. We'll ignore the
* error and store the error to ctx_loss_cnt, which will cause
* dispc_need_ctx_restore() call to return true.
*/
if (board_data->get_context_loss_count)
cnt = board_data->get_context_loss_count(dev);
WARN_ON(cnt < 0);
dispc.ctx_loss_cnt = cnt;
DSSDBG("initial ctx_loss_cnt %u\n", cnt);
}
static bool dispc_need_ctx_restore(void)
{
struct device *dev = &dispc.pdev->dev;
struct omap_display_platform_data *pdata = dev->platform_data;
struct omap_dss_board_info *board_data = pdata->board_data;
int cnt;
/*
* If get_context_loss_count is not available, assume that we need
* context restore always.
*/
if (!board_data->get_context_loss_count)
return true;
cnt = board_data->get_context_loss_count(dev);
if (cnt < 0) {
dev_err(dev, "getting context loss count failed, will force "
"context restore\n");
dispc.ctx_loss_cnt = cnt;
return true;
}
if (cnt == dispc.ctx_loss_cnt)
return false;
DSSDBG("ctx_loss_cnt %d -> %d\n", dispc.ctx_loss_cnt, cnt);
dispc.ctx_loss_cnt = cnt;
return true;
}
int dispc_runtime_get(void)
{
int r;
@ -3709,8 +3691,6 @@ static int omap_dispchw_probe(struct platform_device *pdev)
goto err_irq;
}
dispc_init_ctx_loss_count();
pm_runtime_enable(&pdev->dev);
r = dispc_runtime_get();
@ -3769,8 +3749,7 @@ static int dispc_runtime_resume(struct device *dev)
return r;
clk_enable(dispc.dss_clk);
if (dispc_need_ctx_restore())
dispc_restore_context();
dispc_restore_context();
return 0;
}