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drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos

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[ Upstream commit 15f389da11 ]

Samsung DSIM used in older Exynos SoCs (like Exynos 4210, 4x12, 3250)
doesn't report empty level of packer header FIFO. In case of those SoCs,
use the old way of waiting for empty command tranfsfer FIFO, removed
recently by commit 14806c6415 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer").

Fixes: 14806c6415 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230809145641.3213210-1-m.szyprowski@samsung.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Marek Szyprowski 2023-08-09 16:56:41 +02:00 committed by Greg Kroah-Hartman
parent b86ec59f7d
commit 2f56a02e2a
2 changed files with 17 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
drivers/gpu/drm/bridge/samsung-dsim.c
View File

@ -413,6 +413,7 @@ static const struct samsung_dsim_driver_data exynos3_dsi_driver_data = {
.m_min = 41,
.m_max = 125,
.min_freq = 500,
.has_broken_fifoctrl_emptyhdr = 1,
};
static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
@ -429,6 +430,7 @@ static const struct samsung_dsim_driver_data exynos4_dsi_driver_data = {
.m_min = 41,
.m_max = 125,
.min_freq = 500,
.has_broken_fifoctrl_emptyhdr = 1,
};
static const struct samsung_dsim_driver_data exynos5_dsi_driver_data = {
@ -1010,8 +1012,20 @@ static int samsung_dsim_wait_for_hdr_fifo(struct samsung_dsim *dsi)
do {
u32 reg = samsung_dsim_read(dsi, DSIM_FIFOCTRL_REG);
if (reg & DSIM_SFR_HEADER_EMPTY)
return 0;
if (!dsi->driver_data->has_broken_fifoctrl_emptyhdr) {
if (reg & DSIM_SFR_HEADER_EMPTY)
return 0;
} else {
if (!(reg & DSIM_SFR_HEADER_FULL)) {
/*
* Wait a little bit, so the pending data can
* actually leave the FIFO to avoid overflow.
*/
if (!cond_resched())
usleep_range(950, 1050);
return 0;
}
}
if (!cond_resched())
usleep_range(950, 1050);

1
include/drm/bridge/samsung-dsim.h
View File

@ -53,6 +53,7 @@ struct samsung_dsim_driver_data {
unsigned int plltmr_reg;
unsigned int has_freqband:1;
unsigned int has_clklane_stop:1;
unsigned int has_broken_fifoctrl_emptyhdr:1;
unsigned int num_clks;
unsigned int min_freq;
unsigned int max_freq;