Skip to content

L
linux
Switch branch/tag
  1. 08 Feb, 2015 2 commits
  3. 06 Feb, 2015 10 commits
  5. 02 Feb, 2015 2 commits
  7. 21 Jan, 2015 1 commit
  9. 20 Jan, 2015 4 commits
  11. 16 Jan, 2015 3 commits
  13. 13 Jan, 2015 5 commits
    • Graham Moore's avatar
      mtd: denali: fix incorrect bitmask error in denali_setup_dma · 7c272ac5
      Graham Moore authored 
      commit 3157d1ed ("mtd: denali: remove unnecessary casts") introduced
an error by using a wrong bitmask.

A uint16_t cast was replaced with & 0xff, should be & 0xffff.
Signed-off-by: default avatarGraham Moore <grmoore@opensource.altera.com>
Signed-off-by: default avatarDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      7c272ac5
    • Lee Jones's avatar
      mtd: st_spi_fsm: Fix [-Wsign-compare] build warning · a9b679bf
      Lee Jones authored 
      drivers/mtd/devices/st_spi_fsm.c:1647:17:
  warning: comparison between signed and unsigned integer expressions
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      a9b679bf
    • Lee Jones's avatar
      mtd: st_spi_fsm: Obtain and use EMI clock · 69d5af8d
      Lee Jones authored 
      ST's Common Clk Framework is now available. This patch ensures the FSM
makes use of it by obtaining and enabling the EMI clock. If system fails
to provide the EMI clock, we bomb out.
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      69d5af8d
    • Lee Jones's avatar
      mtd: st_spi_fsm: Extend fsm_clear_fifo to handle unwanted bytes · 5ecd3ea1
      Lee Jones authored 
      Under certain conditions, the SPI-FSM Controller can be left in a state where
the data FIFO is not entirely empty.  This can lead to problems where subsequent
data transfers appear to have been shifted by a number of unidentified bytes.

One simple example would be an errant FSM sequence which loaded more data to the
FIFO than was read by the host.  Another more interesting case results from an
obscure artefact in the FSM Controller.  When switching from data transfers in
x4 or x2 mode to data transfers in x1 mode, extraneous bytes will appear in the
FIFO, unless the previous data transfer was a multiple of 32 cycles (i.e. 8
bytes for x2, and 16 bytes for x4).  This applies equally whether FSM is being
operated directly by a S/W driver, or by the SPI boot-controller in FSM-Boot
mode.  Furthermore, data in the FIFO not only survive a transition between
FSM-Boot and FSM, but also a S/W reset of IP block [1].

By taking certain precautions, it is possible to prevent the driver from causing
this type of problem (e.g. ensuring that the host and programmed sequence
agree on the transfer size, and restricting transfer sizes to multiples of
32-cycles [2]).  However, at the point the driver is loaded, no assumptions can be
made regarding the state of the FIFO.  Even if previous S/W drivers have behaved
correctly, it is impossible to control the number of transactions serviced by
the controller operating in FSM-Boot.

To address this problem, we ensure the FIFO is cleared during initialisation,
before performing any FSM operations.  Previously, the fsm_clear_fifo() code was
capable of detecting and clearing any unwanted 32-bit words from the FIFO.  This
patch extends the capability to handle an arbitrary number of bytes present in
the FIFO [3].  Now that the issue is better understood, we also remove the calls
to fsm_clear_fifo() following the fsm_read() and fsm_write() operations.

The process of actually clearing the FIFO deserves a mention.  While the FIFO
may contain any number of bytes, the SPI_FAST_SEQ_STA register only reports the
number of complete 32-bit words present.  Furthermore, data can only be drained
from the FIFO by reading complete 32-bit words.  With this in mind, a two stage
process is used to the clear the FIFO:

    1. Read any complete 32-bit words from the FIFO, as reported by the
           SPI_FAST_SEQ_STA register.

    2. Mop up any remaining bytes.  At this point, it is not known if there
           are 0, 1, 2, or 3 bytes in the FIFO.  To handle all cases, a dummy
           FSM sequence is used to load one byte at a time, until a complete
           32-bit word is formed; at most, 4 bytes will need to be loaded.

[1] Although this issue has existed since early versions of the SPI-FSM
    controller, its full extent only emerged recently as a consequence of the
    targetpacks starting to use FSM-Boot(x4) as the default configuration.

[2] The requirement to restrict transfers to multiples of 32 cycles was found
    empirically back when DUAL and QUAD mode support was added.  The current
    analysis now gives a satisfactory explanation for this requirement.

[3] Theoretically, it is possible for the FIFO to contain an arbitrary number of
    bits.  However, since there are no known use-cases that leave incomplete
    bytes in the FIFO, only words and bytes are considered here.
Signed-off-by: default avatarAngus Clark <angus.clark@st.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      5ecd3ea1
    • Rickard Strandqvist's avatar
      jffs2: compr_rubin: Remove unused function · e4999bbe
      Rickard Strandqvist authored 
      Remove the function pulledbits() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.
Signed-off-by: default avatarRickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Reviewed-by: default avatarRichard Weinberger <richard@nod.at>
Signed-off-by: default avatarBrian Norris <computersforpeace@gmail.com>
      e4999bbe
  15. 10 Jan, 2015 2 commits
  17. 09 Jan, 2015 4 commits
  19. 08 Jan, 2015 2 commits
  21. 07 Jan, 2015 5 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7