openwrtv4/target/linux/mpc85xx/patches-4.4/200-spi-fsl-espi-preallocate-local-buffer.patch
Felix Fietkau 93a2b8a6c4 mpc85xx: update to linux 4.4, remove unnecessary patches
Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48297
2016-01-17 21:05:19 +00:00

127 lines
4 KiB
Diff

From: Gabor Juhos <juhosg@openwrt.org>
Subject: spi-fsl-espi: avoid frequent high order allocations
The driver allocates 64KiB of memory fro a local buffer before
each transfer and releases that afterwards. When the memory is
fragmented this allocation often fails and causes a warning like
this:
kworker/u2:2: page allocation failure: order:4, mode:0x10c0d0
CPU: 0 PID: 7011 Comm: kworker/u2:2 Not tainted 3.10.24 #1
Workqueue: ffe07000.spi mpc8xxx_spi_work
Call Trace:
[c1c6dcf0] [c0006914] show_stack+0x50/0x170 (unreliable)
[c1c6dd30] [c0259858] dump_stack+0x24/0x34
[c1c6dd40] [c00672e8] warn_alloc_failed+0x120/0x13c
[c1c6dd90] [c0069920] __alloc_pages_nodemask+0x574/0x5c8
[c1c6de20] [c0069990] __get_free_pages+0x1c/0x4c
[c1c6de30] [c0185174] fsl_espi_do_one_msg+0x128/0x2a0
[c1c6de90] [c0184290] mpc8xxx_spi_work+0x50/0x7c
[c1c6dea0] [c0037af8] process_one_work+0x208/0x30c
[c1c6dec0] [c00387a0] worker_thread+0x20c/0x308
[c1c6def0] [c003de60] kthread+0xa4/0xa8
[c1c6df40] [c000c4bc] ret_from_kernel_thread+0x5c/0x64
m25p80 spi0.0: error -12 reading SR
end_request: I/O error, dev mtdblock3, sector 680
SQUASHFS error: squashfs_read_data failed to read block 0x54a4a
SQUASHFS error: Unable to read data cache entry [54a4a]
Preallocate the buffer from the probe routine to avoid
this.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---
drivers/spi/spi-fsl-espi.c | 34 ++++++++++++++++------------------
drivers/spi/spi-fsl-lib.h | 1 +
2 files changed, 17 insertions(+), 18 deletions(-)
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -332,17 +332,13 @@ static void fsl_espi_do_trans(struct spi
static void fsl_espi_cmd_trans(struct spi_message *m,
struct fsl_espi_transfer *trans, u8 *rx_buff)
{
+ struct spi_device *spi = m->spi;
+ struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct spi_transfer *t;
- u8 *local_buf;
+ u8 *local_buf = mspi->local_buf;
int i = 0;
struct fsl_espi_transfer *espi_trans = trans;
- local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
- if (!local_buf) {
- espi_trans->status = -ENOMEM;
- return;
- }
-
list_for_each_entry(t, &m->transfers, transfer_list) {
if (t->tx_buf) {
memcpy(local_buf + i, t->tx_buf, t->len);
@@ -355,16 +351,17 @@ static void fsl_espi_cmd_trans(struct sp
fsl_espi_do_trans(m, espi_trans);
espi_trans->actual_length = espi_trans->len;
- kfree(local_buf);
}
static void fsl_espi_rw_trans(struct spi_message *m,
struct fsl_espi_transfer *trans, u8 *rx_buff)
{
+ struct spi_device *spi = m->spi;
+ struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
struct fsl_espi_transfer *espi_trans = trans;
unsigned int total_len = espi_trans->len;
struct spi_transfer *t;
- u8 *local_buf;
+ u8 *local_buf = mspi->local_buf;
u8 *rx_buf = rx_buff;
unsigned int trans_len;
unsigned int addr;
@@ -373,12 +370,6 @@ static void fsl_espi_rw_trans(struct spi
unsigned int pos;
int i, loop;
- local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
- if (!local_buf) {
- espi_trans->status = -ENOMEM;
- return;
- }
-
for (pos = 0, loop = 0; pos < total_len; pos += trans_len, loop++) {
trans_len = total_len - pos;
@@ -424,8 +415,6 @@ static void fsl_espi_rw_trans(struct spi
else
espi_trans->actual_length += espi_trans->len;
}
-
- kfree(local_buf);
}
static int fsl_espi_do_one_msg(struct spi_master *master,
@@ -673,6 +662,12 @@ static struct spi_master * fsl_espi_prob
mpc8xxx_spi = spi_master_get_devdata(master);
+ mpc8xxx_spi->local_buf = devm_kzalloc(dev, SPCOM_TRANLEN_MAX, GFP_KERNEL);
+ if (!mpc8xxx_spi->local_buf) {
+ ret = -ENOMEM;
+ goto err_probe;
+ }
+
mpc8xxx_spi->reg_base = devm_ioremap_resource(dev, mem);
if (IS_ERR(mpc8xxx_spi->reg_base)) {
ret = PTR_ERR(mpc8xxx_spi->reg_base);
--- a/drivers/spi/spi-fsl-lib.h
+++ b/drivers/spi/spi-fsl-lib.h
@@ -30,6 +30,7 @@ struct mpc8xxx_spi {
void *rx;
#if IS_ENABLED(CONFIG_SPI_FSL_ESPI)
int len;
+ u8 *local_buf;
#endif
int subblock;