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authorThor Thayer <thor.thayer@linux.intel.com>2018-11-16 08:25:49 -0600
committerBoris Brezillon <boris.brezillon@bootlin.com>2018-11-19 22:18:30 +0100
commita6a66f80c85e8e20573ca03fabf32445954a88d5 (patch)
tree8c0bc92c357401ff00b8bf11aded14c0166fa1c0 /drivers/mtd
parentmtd: rawnand: qcom: Namespace prefix some commands (diff)
downloadlinux-dev-a6a66f80c85e8e20573ca03fabf32445954a88d5.tar.xz
linux-dev-a6a66f80c85e8e20573ca03fabf32445954a88d5.zip
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>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/spi-nor/cadence-quadspi.c19
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)