diff options
| author | Thor Thayer <thor.thayer@linux.intel.com> | 2018-11-16 08:25:49 -0600 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@bootlin.com> | 2018-11-19 22:18:30 +0100 |
| commit | a6a66f80c85e8e20573ca03fabf32445954a88d5 (patch) | |
| tree | 8c0bc92c357401ff00b8bf11aded14c0166fa1c0 | |
| parent | 33bf5519ae5dd356b182a94e3622f42860274a38 (diff) | |
| download | linux-a6a66f80c85e8e20573ca03fabf32445954a88d5.tar.bz2 | |
mtd: spi-nor: Fix Cadence QSPI page fault kernel panic
The current Cadence QSPI driver caused a kernel panic sporadically
when writing to QSPI. The problem was caused by writing more bytes
than needed because the QSPI operated on 4 bytes at a time.
<snip>
[ 11.202044] Unable to handle kernel paging request at virtual address bffd3000
[ 11.209254] pgd = e463054d
[ 11.211948] [bffd3000] *pgd=2fffb811, *pte=00000000, *ppte=00000000
[ 11.218202] Internal error: Oops: 7 [#1] SMP ARM
[ 11.222797] Modules linked in:
[ 11.225844] CPU: 1 PID: 1317 Comm: systemd-hwdb Not tainted 4.17.7-d0c45cd44a8f
[ 11.235796] Hardware name: Altera SOCFPGA Arria10
[ 11.240487] PC is at __raw_writesl+0x70/0xd4
[ 11.244741] LR is at cqspi_write+0x1a0/0x2cc
</snip>
On a page boundary limit the number of bytes copied from the tx buffer
to remain within the page.
This patch uses a temporary buffer to hold the 4 bytes to write and then
copies only the bytes required from the tx buffer.
Reported-by: Adrian Amborzewicz <adrian.ambrozewicz@intel.com>
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
| -rw-r--r-- | drivers/mtd/spi-nor/cadence-quadspi.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c index d846428ef038..04cedd3a2bf6 100644 --- a/drivers/mtd/spi-nor/cadence-quadspi.c +++ b/drivers/mtd/spi-nor/cadence-quadspi.c @@ -644,9 +644,23 @@ static int cqspi_indirect_write_execute(struct spi_nor *nor, loff_t to_addr, ndelay(cqspi->wr_delay); while (remaining > 0) { + size_t write_words, mod_bytes; + write_bytes = remaining > page_size ? page_size : remaining; - iowrite32_rep(cqspi->ahb_base, txbuf, - DIV_ROUND_UP(write_bytes, 4)); + write_words = write_bytes / 4; + mod_bytes = write_bytes % 4; + /* Write 4 bytes at a time then single bytes. */ + if (write_words) { + iowrite32_rep(cqspi->ahb_base, txbuf, write_words); + txbuf += (write_words * 4); + } + if (mod_bytes) { + unsigned int temp = 0xFFFFFFFF; + + memcpy(&temp, txbuf, mod_bytes); + iowrite32(temp, cqspi->ahb_base); + txbuf += mod_bytes; + } if (!wait_for_completion_timeout(&cqspi->transfer_complete, msecs_to_jiffies(CQSPI_TIMEOUT_MS))) { @@ -655,7 +669,6 @@ static int cqspi_indirect_write_execute(struct spi_nor *nor, loff_t to_addr, goto failwr; } - txbuf += write_bytes; remaining -= write_bytes; if (remaining > 0) |