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| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2023-08-09 17:56:41 +0300 |
|---|---|---|
| committer | Robert Foss <rfoss@kernel.org> | 2023-08-11 15:54:05 +0300 |
| commit | 15f389da11257b806da75a070cfa41ca0cc15aae (patch) | |
| tree | 04fd814eae2f9bf084e3b5123d4635960f7e3d65 /drivers/gpu/drm/bridge | |
| parent | 96413b355a49fd684430a230479bd231d977894f (diff) | |
| download | linux-15f389da11257b806da75a070cfa41ca0cc15aae.tar.xz | |
drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos
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 14806c641582 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before transfer").
Fixes: 14806c641582 ("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
Diffstat (limited to 'drivers/gpu/drm/bridge')
| -rw-r--r-- | drivers/gpu/drm/bridge/samsung-dsim.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 732caafe5370..b1df91e37b1b 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -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); |