The function mipi_dbi_spi1_transfer() will transfer its payload as 9-bit
data, the 9th (MSB) bit being the data/command bit. In order to do that,
it unpacks the 8-bit values into 16-bit values, then sets the 9th bit if
the byte corresponds to data, clears it otherwise. The 7 MSB are
padding. The array of now 16-bit values is then passed to the SPI core
for transfer.
This function was broken since its introduction, as the length of the
SPI transfer was set to the payload size before its conversion, but the
payload doubled in size due to the 8-bit -> 16-bit conversion.
Fixes: 02dd95fe31 ("drm/tinydrm: Add MIPI DBI support")
Cc: <stable@vger.kernel.org> # 5.4+
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200703141341.1266263-1-paul@crapouillou.net
Recent kernels have been reported to panic using the bochs_drm
framebuffer under qemu-system-sparc64 which was bisected to
commit 7a0483ac4f ("drm/bochs: switch to generic drm fbdev emulation").
The backtrace indicates that the shadow framebuffer copy in
drm_fb_helper_dirty_blit_real() is trying to access the real
framebuffer using a virtual address rather than use an IO access
typically implemented using a physical (ASI_PHYS) access on SPARC.
The fix is to replace the memcpy with memcpy_toio() from io.h.
memcpy_toio() uses writeb() where the original fbdev code
used sbus_memcpy_toio(). The latter uses sbus_writeb().
The difference between writeb() and sbus_memcpy_toio() is
that writeb() writes bytes in little-endian, where sbus_writeb() writes
bytes in big-endian. As endian does not matter for byte writes they are
the same. So we can safely use memcpy_toio() here.
Note that this only fixes bochs, in general fbdev helpers still have
issues with mixing up system memory and __iomem space. Fixing that will
require a lot more work.
v3:
- Improved changelog (Daniel)
- Added FIXME to fbdev_use_iomem (Daniel)
v2:
- Added missing __iomem cast (kernel test robot)
- Made changelog readable and fix typos (Mark)
- Add flag to select iomem - and set it in the bochs driver
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200709193016.291267-1-sam@ravnborg.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200725191012.GA434957@ravnborg.org
Whenever a display update was sent, apart from updating
the memory base address, we called mcde_display_send_one_frame()
which also sent a command to the display requesting the TE IRQ
and enabling the FIFO.
When continuous updates are running this is wrong: we need
to only send this to start the flow to the display on
the very first update. This lead to the display pipeline
locking up and crashing.
Check if the flow is already running and in that case
do not call mcde_display_send_one_frame().
This fixes crashes on the Samsung GT-S7710 (Skomer).
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Stephan Gerhold <stephan@gerhold.net>
Cc: Stephan Gerhold <stephan@gerhold.net>
Cc: stable@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20200718233323.3407670-1-linus.walleij@linaro.org
On boe_nv133fhm_n62 (and presumably on boe_nv133fhm_n61) a scope shows
a small spike on the HPD line right when you power the panel on. The
picture looks something like this:
+--------------------------------------
|
|
|
Power ---+
+---
|
++ |
+----+| |
HPD -----+ +---------------------------+
So right when power is applied there's a little bump in HPD and then
there's small spike right before it goes low. The total time of the
little bump plus the spike was measured on one panel as being 8 ms
long. The total time for the HPD to go high on the same panel was
51.2 ms, though the datasheet only promises it is < 200 ms.
When asked about this glitch, BOE indicated that it was expected and
persisted until the TCON has been initialized.
If this was a real hotpluggable DP panel then this wouldn't matter a
whole lot. We'd debounce the HPD signal for a really long time and so
the little blip wouldn't hurt. However, this is not a hotpluggable DP
panel and the the debouncing logic isn't needed and just shows down
the time needed to get the display working. This is why the code in
panel_simple_prepare() doesn't do debouncing and just waits for HPD to
go high once. Unfortunately if we get unlucky and happen to poll the
HPD line right at the spike we can try talking to the panel before
it's ready.
Let's handle this situation by putting in a 15 ms prepare delay and
decreasing the "hpd absent delay" by 15 ms. That means:
* If you don't have HPD hooked up at all you've still got the
hardcoded 200 ms delay.
* If you've got HPD hooked up you will always wait at least 15 ms
before checking HPD. The only case where this could be bad is if
the panel is sharing a voltage rail with something else in the
system and was already turned on long before the panel came up. In
such a case we'll be delaying 15 ms for no reason, but it's not a
huge delay and I don't see any other good solution to handle that
case.
Even though the delay was measured as 8 ms, 15 ms was chosen to give a
bit of margin.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200716132120.1.I01e738cd469b61fc9b28b3ef1c6541a4f48b11bf@changeid
Looks like I made the mistake of forgetting to check whether or not this
would build without CONFIG_DEBUG_FS, as the Kbuild bot reported some
issues building with tegra_defconfig:
In file included from drivers/gpu/drm/nouveau/nouveau_display.c:47:
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_head_crc_late_register’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:106:47: error: parameter name
omitted
106 | static inline int nv50_head_crc_late_register(struct nv50_head *) {}
| ^~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h:106:54: warning: no return
statement in function returning non-void [-Wreturn-type]
106 | static inline int nv50_head_crc_late_register(struct nv50_head *) {}
| ^~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_handle_vblank’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:108:57: warning: ‘return’ with
a value, in function returning void [-Wreturn-type]
108 | nv50_crc_handle_vblank(struct nv50_head *head) { return 0; }
| ^
./drivers/gpu/drm/nouveau/dispnv50/crc.h:108:1: note: declared here
108 | nv50_crc_handle_vblank(struct nv50_head *head) { return 0; }
| ^~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_check’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:111:23: error: parameter name
omitted
111 | nv50_crc_atomic_check(struct nv50_head *, struct nv50_head_atom *,
| ^~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h:111:43: error: parameter name
omitted
111 | nv50_crc_atomic_check(struct nv50_head *, struct nv50_head_atom *,
| ^~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h:112:9: error: parameter name
omitted
112 | struct nv50_head_atom *) {}
| ^~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h:112:16: warning: no return
statement in function returning non-void [-Wreturn-type]
112 | struct nv50_head_atom *) {}
| ^~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_stop_reporting’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:114:32: error: parameter name
omitted
114 | nv50_crc_atomic_stop_reporting(struct drm_atomic_state *) {}
| ^~~~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_prepare_notifier_contexts’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:116:43: error: parameter name
omitted
116 | nv50_crc_atomic_prepare_notifier_contexts(struct drm_atomic_state *) {}
| ^~~~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_start_reporting’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:118:33: error: parameter name
omitted
118 | nv50_crc_atomic_start_reporting(struct drm_atomic_state *) {}
| ^~~~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_set’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:120:21: error: parameter name
omitted
120 | nv50_crc_atomic_set(struct nv50_head *, struct nv50_head_atom *) {}
| ^~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h:120:41: error: parameter name
omitted
120 | nv50_crc_atomic_set(struct nv50_head *, struct nv50_head_atom *) {}
| ^~~~~~~~~~~~~~~~~~~~~~~
./drivers/gpu/drm/nouveau/dispnv50/crc.h: In function
‘nv50_crc_atomic_clr’:
./drivers/gpu/drm/nouveau/dispnv50/crc.h:122:21: error: parameter name
omitted
122 | nv50_crc_atomic_clr(struct nv50_head *) {}
| ^~~~~~~~~~~~~~~~~~
drivers/gpu/drm/nouveau/nouveau_display.c: In function
‘nouveau_framebuffer_new’:
drivers/gpu/drm/nouveau/nouveau_display.c:286:15: warning: variable
‘width’ set but not used [-Wunused-but-set-variable]
286 | unsigned int width, height, i;
| ^~~~~
So, fix the inline function declarations we use in
drm/drivers/gpu/drm/nouveau/dispnv50/crc.h when CONFIG_DEBUG_FS is
enabled.
Fixes: 12885ecbfe ("drm/nouveau/kms/nvd9-: Add CRC support")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
