Re: [PATCH v4] drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos
On 17/08/2023 08:06, Marek Szyprowski wrote:
On 11.08.2023 14:59, Robert Foss wrote:
On Wed, 9 Aug 2023 16:56:41 +0200, Marek Szyprowski wrote:
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 ("Drain command transfer FIFO before
transfer").
[...]
Fixed formatting warning related to commit message syntax.
Applied, thanks!
Thanks for applying it, but yesterday I've noticed that this patch has
been dropped from linux-next for some unknown reasons. I also cannot
find it in today's linux-next (next-20230817):
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/drivers/gpu/drm/bridge/samsung-dsim.c?h=next-20230817
Any idea what has happened?
Rob applied it too late, the last drm-misc-next PR was sent before this patch
was applied,
and the dim process
(https://drm.pages.freedesktop.org/maintainer-tools/index.html) automatically
merges drm-misc-next-fixes instead of drm-misc-next after -rc6,
drm-misc-next-fixes is aligned
with the last drm-misc-next PR before -rc6.
But the patch is still in drm-misc-next since it never closes
Neil
Best regards
Re: [PATCH v4] drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos
On 11.08.2023 14:59, Robert Foss wrote:
> On Wed, 9 Aug 2023 16:56:41 +0200, Marek Szyprowski wrote:
>> 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 ("Drain command transfer FIFO before
>> transfer").
>>
>>
>> [...]
> Fixed formatting warning related to commit message syntax.
>
> Applied, thanks!
Thanks for applying it, but yesterday I've noticed that this patch has
been dropped from linux-next for some unknown reasons. I also cannot
find it in today's linux-next (next-20230817):
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/drivers/gpu/drm/bridge/samsung-dsim.c?h=next-20230817
Any idea what has happened?
Best regards
--
Marek Szyprowski, PhD
Samsung R Institute Poland
Re: [PATCH v4] drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos
On Wed, 9 Aug 2023 16:56:41 +0200, Marek Szyprowski wrote:
> 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 ("Drain command transfer FIFO before
> transfer").
>
>
> [...]
Fixed formatting warning related to commit message syntax.
Applied, thanks!
[1/1] drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on
older Exynos
https://cgit.freedesktop.org/drm/drm-misc/commit/?id=15f389da1125
Rob
Re: [PATCH v4] drm: bridge: samsung-dsim: Fix waiting for empty cmd transfer FIFO on older Exynos
On 8/9/23 16:56, Marek Szyprowski wrote:
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 ("Drain command transfer FIFO before
transfer").
Fixes: 14806c641582 ("drm: bridge: samsung-dsim: Drain command transfer FIFO before
transfer")
Signed-off-by: Marek Szyprowski
Oh, nice, there is already a bitfield piece in place.
Thanks !
Reviewed-by: Marek Vasut
[PATCH v4] 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 ("Drain command transfer FIFO before
transfer").
Fixes: 14806c641582 ("drm: bridge: samsung-dsim: Drain command transfer FIFO
before transfer")
Signed-off-by: Marek Szyprowski
---
v4:
- made has_broken_fifoctrl_emptyhdr a bitfield
v3:
- fixed 'fixes' tag, added reviewed-by
v2:
- added additional delay when workaround is used as suggested by Marek Vasut
v1:
https://lore.kernel.org/all/20230718131859.3114135-1-m.szyprow...@samsung.com/
---
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 ("Drain command transfer FIFO before
transfer").
Fixes: 14806c641582 ("Drain command transfer FIFO before transfer")
Signed-off-by: Marek Szyprowski
---
drivers/gpu/drm/bridge/samsung-dsim.c | 18 --
include/drm/bridge/samsung-dsim.h | 1 +
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
b/drivers/gpu/drm/bridge/samsung-dsim.c
index c49091691ab1..35d29f6cd3e2 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);
diff --git a/include/drm/bridge/samsung-dsim.h
b/include/drm/bridge/samsung-dsim.h
index 05100e91ecb9..6fc9bb2979e4 100644
--- a/include/drm/bridge/samsung-dsim.h
+++ b/include/drm/bridge/samsung-dsim.h
@@ -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;
--
2.34.1
