[libcamera-devel] [PATCH v3 2/3] android: camera_buffer: Map buffer in the first plane() call
Hirokazu Honda
hiroh at chromium.org
Fri Aug 27 08:57:08 CEST 2021
Hi Laurent,
On Thu, Aug 26, 2021 at 9:06 PM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Hiro,
>
> Thank you for the patch.
>
> On Thu, Aug 26, 2021 at 05:00:20PM +0900, Hirokazu Honda wrote:
> > CameraBuffer implementation maps a given buffer_handle_t in
> > constructor. Mapping is redundant to only know the plane info like
> > stride and offset. Mapping should be executed rater in the first
> > plane() call.
> >
> > Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> > ---
> > src/android/mm/cros_camera_buffer.cpp | 71 +++++++++++--------
> > src/android/mm/generic_camera_buffer.cpp | 86 ++++++++++++++++--------
> > 2 files changed, 100 insertions(+), 57 deletions(-)
> >
> > diff --git a/src/android/mm/cros_camera_buffer.cpp b/src/android/mm/cros_camera_buffer.cpp
> > index 50732637..ba6650cf 100644
> > --- a/src/android/mm/cros_camera_buffer.cpp
> > +++ b/src/android/mm/cros_camera_buffer.cpp
> > @@ -25,7 +25,7 @@ public:
> > int flags);
> > ~Private();
> >
> > - bool isValid() const { return valid_; }
> > + bool isValid() const { return registered_; }
> >
> > unsigned int numPlanes() const;
> >
> > @@ -34,10 +34,12 @@ public:
> > size_t jpegBufferSize(size_t maxJpegBufferSize) const;
> >
> > private:
> > + void map();
> > +
> > cros::CameraBufferManager *bufferManager_;
> > buffer_handle_t handle_;
> > unsigned int numPlanes_;
> > - bool valid_;
> > + bool mapped_;
> > bool registered_;
> > union {
> > void *addr;
> > @@ -50,7 +52,7 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
> > [[maybe_unused]] libcamera::PixelFormat pixelFormat,
> > [[maybe_unused]] const libcamera::Size &size,
> > [[maybe_unused]] int flags)
> > - : handle_(camera3Buffer), numPlanes_(0), valid_(false),
> > + : handle_(camera3Buffer), numPlanes_(0), mapped_(false),
> > registered_(false)
> > {
> > bufferManager_ = cros::CameraBufferManager::GetInstance();
> > @@ -63,36 +65,11 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
> >
> > registered_ = true;
> > numPlanes_ = bufferManager_->GetNumPlanes(camera3Buffer);
> > - switch (numPlanes_) {
> > - case 1: {
> > - ret = bufferManager_->Lock(handle_, 0, 0, 0, 0, 0, &mem.addr);
> > - if (ret) {
> > - LOG(HAL, Error) << "Single plane buffer mapping failed";
> > - return;
> > - }
> > - break;
> > - }
> > - case 2:
> > - case 3: {
> > - ret = bufferManager_->LockYCbCr(handle_, 0, 0, 0, 0, 0,
> > - &mem.ycbcr);
> > - if (ret) {
> > - LOG(HAL, Error) << "YCbCr buffer mapping failed";
> > - return;
> > - }
> > - break;
> > - }
> > - default:
> > - LOG(HAL, Error) << "Invalid number of planes: " << numPlanes_;
> > - return;
> > - }
> > -
> > - valid_ = true;
> > }
> >
> > CameraBuffer::Private::~Private()
> > {
> > - if (valid_)
> > + if (mapped_)
> > bufferManager_->Unlock(handle_);
> > if (registered_)
> > bufferManager_->Deregister(handle_);
> > @@ -105,6 +82,11 @@ unsigned int CameraBuffer::Private::numPlanes() const
> >
> > Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
> > {
> > + if (!mapped_)
> > + map();
> > + if (!mapped_)
> > + return {};
> > +
> > void *addr;
> >
> > switch (numPlanes()) {
> > @@ -134,4 +116,35 @@ size_t CameraBuffer::Private::jpegBufferSize([[maybe_unused]] size_t maxJpegBuff
> > return bufferManager_->GetPlaneSize(handle_, 0);
> > }
> >
> > +void CameraBuffer::Private::map()
> > +{
> > + int ret;
> > + switch (numPlanes_) {
> > + case 1: {
> > + ret = bufferManager_->Lock(handle_, 0, 0, 0, 0, 0, &mem.addr);
> > + if (ret) {
> > + LOG(HAL, Error) << "Single plane buffer mapping failed";
> > + return;
> > + }
> > + break;
> > + }
> > + case 2:
> > + case 3: {
> > + ret = bufferManager_->LockYCbCr(handle_, 0, 0, 0, 0, 0,
> > + &mem.ycbcr);
> > + if (ret) {
> > + LOG(HAL, Error) << "YCbCr buffer mapping failed";
> > + return;
> > + }
> > + break;
> > + }
> > + default:
> > + LOG(HAL, Error) << "Invalid number of planes: " << numPlanes_;
> > + return;
> > + }
> > +
> > + mapped_ = true;
> > + return;
> > +}
> > +
> > PUBLIC_CAMERA_BUFFER_IMPLEMENTATION
> > diff --git a/src/android/mm/generic_camera_buffer.cpp b/src/android/mm/generic_camera_buffer.cpp
> > index 22753490..cfe55b69 100644
> > --- a/src/android/mm/generic_camera_buffer.cpp
> > +++ b/src/android/mm/generic_camera_buffer.cpp
> > @@ -37,6 +37,18 @@ public:
> > size_t jpegBufferSize(size_t maxJpegBufferSize) const;
> >
> > private:
> > + struct PlaneInfo {
> > + unsigned int offset;
> > + unsigned int size;
> > + };
> > +
> > + void map();
> > +
> > + int fd_;
> > + int flags_;
> > + off_t bufferLength_;
> > + bool mapped_;
> > + std::vector<PlaneInfo> planeInfo_;
> > /* \todo Remove planes_ when it will be added to MappedBuffer */
> > std::vector<Span<uint8_t>> planes_;
> > };
> > @@ -45,6 +57,7 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
> > buffer_handle_t camera3Buffer,
> > libcamera::PixelFormat pixelFormat,
> > const libcamera::Size &size, int flags)
> > + : fd_(-1), flags_(flags), mapped_(false)
>
> This should initialize bufferLength_ to 0, otherwise the ASSERT()s that
> checks the variable will be pointless if the constructor returns an
> error before setting bufferLength_.
>
Shall I set bufferLength to -1 and then ASSERT(bufferLength_ >= 0), or
set to 0 and ASSERT(bufferLength > 0)?
-Hiro
> And it will also avoid a Coverity warning :-)
>
> I can handle this when pushing the series.
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>
> > {
> > error_ = 0;
> >
> > @@ -61,43 +74,35 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
> > * now that the buffer is backed by a single dmabuf, with planes being
> > * stored contiguously.
> > */
> > - int fd = -1;
> > for (int i = 0; i < camera3Buffer->numFds; i++) {
> > - if (camera3Buffer->data[i] == -1 || camera3Buffer->data[i] == fd)
> > + if (camera3Buffer->data[i] == -1 || camera3Buffer->data[i] == fd_)
> > continue;
> >
> > - if (fd != -1) {
> > + if (fd_ != -1) {
> > error_ = -EINVAL;
> > LOG(HAL, Error) << "Discontiguous planes are not supported";
> > return;
> > }
> >
> > - fd = camera3Buffer->data[i];
> > + fd_ = camera3Buffer->data[i];
> > }
> >
> > - if (fd == -1) {
> > + if (fd_ == -1) {
> > error_ = -EINVAL;
> > LOG(HAL, Error) << "No valid file descriptor";
> > return;
> > }
> >
> > - off_t bufferLength = lseek(fd, 0, SEEK_END);
> > - if (bufferLength < 0) {
> > + bufferLength_ = lseek(fd_, 0, SEEK_END);
> > + if (bufferLength_ < 0) {
> > error_ = -errno;
> > LOG(HAL, Error) << "Failed to get buffer length";
> > return;
> > }
> >
> > - void *address = mmap(nullptr, bufferLength, flags, MAP_SHARED, fd, 0);
> > - if (address == MAP_FAILED) {
> > - error_ = -errno;
> > - LOG(HAL, Error) << "Failed to mmap plane";
> > - return;
> > - }
> > - maps_.emplace_back(static_cast<uint8_t *>(address), bufferLength);
> > -
> > const unsigned int numPlanes = info.numPlanes();
> > - planes_.resize(numPlanes);
> > + planeInfo_.resize(numPlanes);
> > +
> > unsigned int offset = 0;
> > for (unsigned int i = 0; i < numPlanes; ++i) {
> > /*
> > @@ -109,17 +114,17 @@ CameraBuffer::Private::Private([[maybe_unused]] CameraBuffer *cameraBuffer,
> > const unsigned int planeSize =
> > stride * ((size.height + vertSubSample - 1) / vertSubSample);
> >
> > - planes_[i] = libcamera::Span<uint8_t>(
> > - static_cast<uint8_t *>(address) + offset, planeSize);
> > + planeInfo_[i].offset = offset;
> > + planeInfo_[i].size = planeSize;
> >
> > - if (bufferLength < offset + planeSize) {
> > - error_ = -EINVAL;
> > - LOG(HAL, Error) << "Plane " << i << " is out of buffer"
> > - << ", buffer length=" << bufferLength
> > - << ", offset=" << offset
> > - << ", size=" << planeSize;
> > + if (bufferLength_ < offset + planeSize) {
> > + LOG(HAL, Error) << "Plane " << i << " is out of buffer:"
> > + << " plane offset=" << offset
> > + << ", plane size=" << planeSize
> > + << ", buffer length=" << bufferLength_;
> > return;
> > }
> > +
> > offset += planeSize;
> > }
> > }
> > @@ -130,12 +135,14 @@ CameraBuffer::Private::~Private()
> >
> > unsigned int CameraBuffer::Private::numPlanes() const
> > {
> > - return planes_.size();
> > + return planeInfo_.size();
> > }
> >
> > Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
> > {
> > - if (plane >= planes_.size())
> > + if (!mapped_)
> > + map();
> > + if (!mapped_)
> > return {};
> >
> > return planes_[plane];
> > @@ -143,8 +150,31 @@ Span<uint8_t> CameraBuffer::Private::plane(unsigned int plane)
> >
> > size_t CameraBuffer::Private::jpegBufferSize(size_t maxJpegBufferSize) const
> > {
> > - return std::min<unsigned int>(maps_[0].size(),
> > - maxJpegBufferSize);
> > + ASSERT(bufferLength_ >= 0);
> > +
> > + return std::min<unsigned int>(bufferLength_, maxJpegBufferSize);
> > +}
> > +
> > +void CameraBuffer::Private::map()
> > +{
> > + ASSERT(fd_ != -1);
> > + ASSERT(bufferLength_ >= 0);
> > +
> > + void *address = mmap(nullptr, bufferLength_, flags_, MAP_SHARED, fd_, 0);
> > + if (address == MAP_FAILED) {
> > + error_ = -errno;
> > + LOG(HAL, Error) << "Failed to mmap plane";
> > + return;
> > + }
> > + maps_.emplace_back(static_cast<uint8_t *>(address), bufferLength_);
> > +
> > + planes_.reserve(planeInfo_.size());
> > + for (const auto &info : planeInfo_) {
> > + planes_.emplace_back(
> > + static_cast<uint8_t *>(address) + info.offset, info.size);
> > + }
> > +
> > + mapped_ = true;
> > }
> >
> > PUBLIC_CAMERA_BUFFER_IMPLEMENTATION
>
> --
> Regards,
>
> Laurent Pinchart
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