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| author | Simon Glass <sjg@chromium.org> | 2019-05-18 11:59:54 -0600 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2019-07-10 16:52:58 -0600 |
| commit | ca2abb75a086d8b0bdb51689f331ba8f1a146379 (patch) | |
| tree | e6afa389d92309be6d002a4eec41a59d7f2b3e66 /drivers/spi/spi-mem.c | |
| parent | 731ba3c0beaf4318cc97ece1e422a61fc5721f5b (diff) | |
| download | u-boot-ca2abb75a086d8b0bdb51689f331ba8f1a146379.zip u-boot-ca2abb75a086d8b0bdb51689f331ba8f1a146379.tar.gz u-boot-ca2abb75a086d8b0bdb51689f331ba8f1a146379.tar.bz2 | |
spi: Avoid using malloc() in a critical function
In general we should avoid calling malloc() and free() repeatedly in
U-Boot lest we turn it into tianocore. In SPL this can make SPI flash
unusable since free() is often a nop and allocation space is limited.
In any case, these seems no need for malloc() since the number of bytes
is very small, perhaps less than 8.
Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: d13f5b254a (spi: Extend the core to ease integration of SPI
memory controllers)
Diffstat (limited to 'drivers/spi/spi-mem.c')
| -rw-r--r-- | drivers/spi/spi-mem.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index b86eee7..7aabebe 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -201,7 +201,6 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op) unsigned int pos = 0; const u8 *tx_buf = NULL; u8 *rx_buf = NULL; - u8 *op_buf; int op_len; u32 flag; int ret; @@ -338,7 +337,17 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op) } op_len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes; - op_buf = calloc(1, op_len); + + /* + * Avoid using malloc() here so that we can use this code in SPL where + * simple malloc may be used. That implementation does not allow free() + * so repeated calls to this code can exhaust the space. + * + * The value of op_len is small, since it does not include the actual + * data being sent, only the op-code and address. In fact, it should be + * possible to just use a small fixed value here instead of op_len. + */ + u8 op_buf[op_len]; op_buf[pos++] = op->cmd.opcode; @@ -382,8 +391,6 @@ int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op) debug("%02x ", tx_buf ? tx_buf[i] : rx_buf[i]); debug("[ret %d]\n", ret); - free(op_buf); - if (ret < 0) return ret; #endif /* __UBOOT__ */ |