In function qxl_release_alloc(), when kmalloc() returns a NULL pointer,
it returns value 0 and parameter *ret is uninitialized. 0 means no error
to the callers of qxl_release_alloc(). The callers keep going and will
try to reference the uninitialized variable. This patch fixes the bug,
returning "-ENOMEM" when kmalloc() fails.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188911
Signed-off-by: Pan Bian <bianpan2016@163.com>
[seanpaul fixed up subject prefix]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1480777902-7648-1-git-send-email-bianpan2016@163.com
According to the documentation, the PHYs supported by this driver
can also support pause frames. Announce this to be so.
Tested with a TI83822I.
Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For ASoC Intel SST Atom based devices a sysfs entry is created
in order to track FW version. The FW version is useful in order to
check the different Version of LPE DSP FW across Intel SoCs.
Signed-off-by: Sebastien Guiriec <sebastien.guiriec@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
After the boot of the SST FW the firmware version is send back
to the driver. This patch is saving the FW version inside the
driver.
Signed-off-by: Sebastien Guiriec <sebastien.guiriec@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch is adding a sysfs entry in order to be able to get
access to SST FW version.
Signed-off-by: Sebastien Guiriec <sebastien.guiriec@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
These regualtors output 0v when vsel is 0. The datasheet will be updated
to reflect this.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Use module_platform_driver for the e820 driver instead of open-coding it.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently, each hub class request constant is defined by a line like:
#define ClearHubFeature (0x2000 | USB_REQ_CLEAR_FEATURE)
The "magic" number for the high byte is one of 0x20, 0xa0, 0x23, 0xa3.
The 0x80 bit that changes inditace USB_DIR_IN, and the 0x03 that
pops up is the difference between USB_RECIP_DEVICE (0x00) and
USB_RECIP_OTHER (0x03). The constant 0x20 bit is USB_TYPE_CLASS.
This patch eliminates those magic numbers by defining a macro to help
construct these hub class request from simpler constants.
Note that USB_RT_HUB is defined as (USB_TYPE_CLASS | USB_RECIP_DEVICE)
and that USB_RT_PORT is defined as (USB_TYPE_CLASS | USB_RECIP_OTHER).
Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ohci_hcd_pxa27x_drv_probe function is not doing anything other
than calling usb_hcd_pxa27x_probe function so ohci_hcd_pxa27x_drv_probe
function is useless that is why removed ohci_hcd_pxa27x_drv_probe
function and renamed usb_hcd_pxa27x_probe function to
ohci_hcd_pxa27x_drv_probe for proper naming.
The ohci_hcd_pxa27x_remove function is also not doing anything other than
calling usb_hcd_pxa27x_remove that is why removed ohci_hcd_pxa27x_remove
function and renamed usb_hcd_pxa27x_remove to ohci_hcd_pxa27x_remove for
proper naming.
Signed-off-by: Manjunath Goudar <csmanjuvijay@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ohci_hcd_omap_drv_probe and ohci_hcd_omap_drv_remove
functions are removed as these are useless functions except calling
usb_hcd_omap_probe and usb_hcd_omap_remove functions.
The usb_hcd_omap_probe function renamed to ohci_hcd_omap_probe
and usb_hcd_omap_remove function renamed to ohci_hcd_omap_remove
for proper naming.
Signed-off-by: Manjunath Goudar <csmanjuvijay@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ohci_hcd_s3c2410_drv_probe and ohci_hcd_s3c2410_drv_remove
functions are removed as these are useless functions except calling
usb_hcd_s3c2410_probe and usb_hcd_s3c2410_remove functions.
The usb_hcd_s3c2410_probe function renamed to ohci_hcd_s3c2410_drv_probe
and usb_hcd_s3c2410_remove function renamed to ohci_hcd_s3c2410_drv_remove
for proper naming.
Signed-off-by: Manjunath Goudar <csmanjuvijay@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit e73c23ff73 ("block: add async variant of
blkdev_issue_zeroout") messages like the following show up:
EXT4-fs (dm-1): Delayed block allocation failed for inode 2368848 at
logical offset 0 with max blocks 1 with error 95
EXT4-fs (dm-1): This should not happen!! Data will be lost
Due to the following fallthrough introduced with
commit 2d253440b5 ("block: Define zoned block device operations"),
generic_make_request_checks() would accept a REQ_OP_WRITE_SAME bio only
if the block device supports "write same" *and* is a zoned one:
switch (bio_op(bio)) {
[...]
case REQ_OP_WRITE_SAME:
if (!bdev_write_same(bio->bi_bdev))
goto not_supported;
case REQ_OP_ZONE_REPORT:
case REQ_OP_ZONE_RESET:
if (!bdev_is_zoned(bio->bi_bdev))
goto not_supported;
break;
[...]
}
Thus, although the bio setup as done by __blkdev_issue_write_same() from
commit e73c23ff73 ("block: add async variant of blkdev_issue_zeroout")
would succeed, its actual submission would not, resulting in the
EOPNOTSUPP == 95.
Fix this by removing the fallthrough which, due to the lack of an explicit
comment, seems to be unintended anyway.
Fixes: e73c23ff73 ("block: add async variant of blkdev_issue_zeroout")
Fixes: 2d253440b5 ("block: Define zoned block device operations")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
We'll want to decouple the vlv/chv wm register reprogramming from any
single pipe. So let's just write all the DDL registers in one go. We
already write all the wm registers anyway since the bits are sprinkled
all over the place and so writing them for just a single pipe would have
been too messy anyway.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-14-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
On VLV/CHV some of the watermark values are split across two registers:
low order bits in one, and high order bits in another. So we may not be
able to update a single watermark value atomically, and thus we must be
careful that we don't temporarily introduce out of bounds values during
the reprogramming. To prevent this we can simply zero out all the high
order bits initially, then we update the low order bits, and finally
we update the high order bits with the final value.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-13-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Before we attempt to turn any planes on or off we must first exit
csxr. That's due to cxsr effectively making the plane enable bits
read-only. Currently we achieve that with a vblank wait right after
toggling the cxsr enable bit. We do the vblank wait even if cxsr was
already off, which seems wasteful, so let's try to only do it when
absolutely necessary.
We could start tracking the cxsr state fully somewhere, but for now
it seems easiest to just have intel_set_memory_cxsr() return the
previous cxsr state.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-11-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Let's protect the cxsr state with the wm_mutex, since it might
get poked from multiple places if there's a parallel plane update
happening with a pipe getting enable/disabled.
It's still pretty racy for the old platforms, but for vlv/chv it
should work, I think. If not, we'll improve it later anyway.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-10-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Store the vlv/chv watermark values in straight up arrays indexed by
enum plane_id. Avoids a lot of useless checks for the plane type when
we don't have to think which structure member we need to access.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-7-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Let's compute the maxfifo watermarks using max() instead of min().
Can't even recall why I did it the other way originally. Anyways
using max() avoids having to initialize the watermarks to the max
value first.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-5-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
ilk_disable_lp_wm() will tell us whether the LP1+ watermarks were
disabled or not, and hence whether we need to for the vblank wait or
not. Let's use that information to eliminate some useless vblank
waits.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-3-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
HSW+ all use the .initial_watermarks() hook, so there's no point in
calling intel_update_watermarks() from HSW+ specific code. We'll still
hang on to the .initial_watermarks NULL check since theoretically if the
memory latencies are not populated we would not populate the function
pointer either.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480354637-14209-2-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Not validating the mode rate against max. link rate results in not pruning
invalid modes. For e.g, a HBR2 5.4 Gbps 2-lane configuration does not
support 4k@60Hz. But, we do not reject this mode.
So, make use of the helpers in intel_dp to validate mode data rate against
max. link data rate of a configuration.
v3: Renamed local variables again for consistency (Manasi)
v2: Renamed mode data rate local variable to be more explanatory.
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479243546-17189-1-git-send-email-dhinakaran.pandiyan@intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
We store DP link rates as link clock frequencies in kHz, just like all
other clock values. But, DP link rates in the DP Spec. are expressed in
Gbps/lane, which seems to have led to some confusion.
E.g., for HBR2
Max. data rate = 5.4 Gbps/lane x 4 lane x 8/10 x 1/8 = 2160000 kBps
where, 8/10 is for channel encoding and 1/8 is for bit to Byte conversion
Using link clock frequency, like we do
Max. data rate = 540000 kHz * 4 lanes = 2160000 kSymbols/s
Because, each symbol has 8 bit of data, this is 2160000 kBps
and there is no need to account for channel encoding here.
But, currently we do 540000 kHz * 4 lanes * (8/10) = 1728000 kBps
Similarly, while computing the required link bandwidth for a mode,
there is a mysterious 1/10 term.
This should simply be pixel_clock kHz * (bpp/8) to give the final result in
kBps
v2: Changed to DIV_ROUND_UP() and comment changes (Ville)
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479160220-17794-1-git-send-email-dhinakaran.pandiyan@intel.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
The EHCI specification states the following in the SUSP bit description:
In the Suspend state, the port is sensitive to resume detection.
Note that the bit status does not change until the port is suspended and
that there may be a delay in suspending a port if there is a transaction
currently in progress on the USB.
However, in NXP USBDR controller, the PORTSCx[SUSP] bit changes immediately
when the application sets it and not when the port is actually suspended.
So the application must wait for at least 10 milliseconds after a port
indicates that it is suspended, to make sure this port has entered
suspended state before initiating this port resume using the Force Port
Resume bit. This bit is for NXP controller, not EHCI compatible.
Signed-off-by: Changming Huang <jerry.huang@nxp.com>
Signed-off-by: Ramneek Mehresh <ramneek.mehresh@nxp.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a system with a defective USB device connected to an USB hub,
an endless sequence of port connect events was observed. The sequence
of events as observed is as follows:
- Port reports connected event (port status=USB_PORT_STAT_CONNECTION).
- Event handler debounces port and resets it by calling hub_port_reset().
- hub_port_reset() calls hub_port_wait_reset() to wait for the reset
to complete.
- The reset completes, but USB_PORT_STAT_CONNECTION is not immediately
set in the port status register.
- hub_port_wait_reset() returns -ENOTCONN.
- Port initialization sequence is aborted.
- A few milliseconds later, the port again reports a connected event,
and the sequence repeats.
This continues either forever or, randomly, stops if the connection
is already re-established when the port status is read. It results in
a high rate of udev events. This in turn destabilizes userspace since
the above sequence holds the device mutex pretty much continuously
and prevents userspace from actually reading the device status.
To prevent the problem from happening, let's wait for the connection
to be re-established after a port reset. If the device was actually
disconnected, the code will still return an error, but it will do so
only after the long reset timeout.
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Current implementation of init_vudc_hw() adds ep0 to ep_list
and then after looping through all endpoints removes it from
that list.
As this may be misleading let's refactor this function
and avoid adding and removing ep0 to eplist and place it
immediately in correct place.
In addition let's remove redundant 0 assignments as ep
array is zeroed during allocation.
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ep_list inside gadget structure doesn't contain ep0.
It is stored separately in ep0 field.
This causes an urb hang if gadget driver decides to
delay setup handling. On host side this is visible as
timeout error when setting configuration.
This bug can be reproduced using for example any gadget
with mass storage function.
Fixes: abdb295743 ("usbip: vudc: Add vudc_transfer")
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Silence this warning emitted by sphinx:
include/linux/device.h:938: warning: No description found for parameter 'links'
While at it, fix typos in comments of device links code.
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Silvio Fricke <silvio.fricke@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using regmap_update_bits(..., mask, 1) with 'mask' following (1 << k)
and k greater than 0 is wrong. Indeed, _regmap_update_bits will perform
(mask & 1), which results in 0 if LSB of mask is 0. Thus the call
regmap_update_bits(..., mask, 1) is in reality equivalent to
regmap_update_bits(..., mask, 0).
In such a case, the correct use is regmap_update_bits(..., mask, mask).
This driver is performing such a mistake with the CS42L56_AIN*_REF_MASK
masks, which equal 0x10, 0x20, 0x40 and 0x80. Fix the driver to make it
consistent with the API. Please note that this change is untested,
as I do not have this piece of hardware. Testers are welcome!
Signed-off-by: Florian Vaussard <florian.vaussard@heig-vd.ch>
Reviewed-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Brian Austin <brian.austin@cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch will check the type of embedded controls for a widget, and
only free the TLV of volume mixers. Bytes controls don't have TLV.
Just free the private value which is used as struct soc_mixer_control
for volume mixers or soc_bytes_ext for bytes controls. No need to cast
to these types before freeing it.
Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This patch can create multiple enumerated mixer controls for a widget.
Previously topology kernel driver assumes a widget can have only one
emumerated mixer control. We need to remove this restriction for Broxton.
Its firmware modules (widgets) may need multiple enum controls based on
the channel and MIC combination.
No ABI change is needed. The ABI allows a widget to embed multiple
controls.
Reported-by: G Kranthi <gudishax.kranthikumar@intel.com>
Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Tidy the tuning loop by moving it to a separate function and making it a
for-loop.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
There are only 2 possible block sizes, so simplify 2 if-statements into 1.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Factor out some functions to tidy up the code in sdhci_execute_tuning.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Use mmc_abort_tuning() instead of open-coding the stop command.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If a tuning command times out, the card could still be processing it, which
will cause problems for recovery. The eMMC specification says that CMD12
can be used to stop CMD21, so add a function that does that.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
SDHCI falls back to fixed sampling if there is an error during tuning.
However it also reports an error unless there is periodic re-tuning.
That is not the best option because:
a) there is a reasonable chance that fixed sampling will work, especially
at room temperature.
b) re-tuning will be done again anyway if there are CRC errors.
Change to return no error always when falling back to fixed sampling.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
If the driver has exhausted the maximum number of tuning loops, then fixed
sampling is used. To do that both SDHCI_CTRL_TUNED_CLK and
SDHCI_CTRL_EXEC_TUNING must be reset to 0, but only SDHCI_CTRL_TUNED_CLK
was being reset. Reset SDHCI_CTRL_EXEC_TUNING to 0 also.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Clearing the tuning bits should reset the tuning circuit. However there is
more to do. Reset the command and data lines for good measure, and then
for eMMC ensure the card is not still trying to process a tuning command by
sending a stop command.
Note the JEDEC eMMC specification says the stop command (CMD12) can be used
to stop a tuning command (CMD21) whereas the SD specification is silent on
the subject with respect to the SD tuning command (CMD19). Considering that
CMD12 is not a valid SDIO command, the stop command is sent only when the
tuning command is CMD21 i.e. for eMMC. That addresses cases seen so far
which have been on eMMC.
Note that this replaces the commit fe5fb2e3b5 ("mmc: sdhci: Reset cmd and
data circuits after tuning failure") which is being reverted for v4.9+.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Dan O'Donovan <dan@emutex.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This reverts commit fe5fb2e3b5 ("mmc: sdhci: Reset cmd and data circuits
after tuning failure").
A better fix is available, and it will be applied to older stable releases,
so get this out of the way by reverting it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The JEDEC specification indicates CMD13 can be used after a HS200 switch
to check for errors. However in practice some boards experience CRC errors
in the CMD13 response. Consequently, for HS200, CRC errors are not a
reliable way to know the switch failed. If there really is a problem, we
would expect tuning will fail and the result ends up the same. So change
the error condition to ignore CRC errors in that case.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Commit aeefb36832 ("drm/exynos: gsc: add device tree support and remove
usage of static mappings") made the DRM_EXYNOS_GSC Kconfig symbol to only
be selectable if the exynos-gsc V4L2 driver isn't enabled, since both use
the same HW IP block.
But added the dependency as depends on !VIDEO_SAMSUNG_EXYNOS_GSC which is
not correct since Kconfig expressions are not boolean but tristate. So it
will only evaluate to 'n' if VIDEO_SAMSUNG_EXYNOS_GSC=y but will evaluate
to 'm' if VIDEO_SAMSUNG_EXYNOS_GSC=m.
This means that both the V4L2 and DRM drivers can be enabled if the former
is enabled as a module, which isn't what we want since otherwise 2 drivers
could attempt to use the hardware at the same time.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>