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Date: Fri, 12 Dec 2008 12:51:01 +0000
From: Ben Hutchings <bhutchings@...arflare.com>
To: David Miller <davem@...emloft.net>
Cc: netdev@...r.kernel.org, linux-net-drivers@...arflare.com
Subject: [PATCH 07/33] sfc: Clean up waits for flash/EEPROM operations
Make falcon_spi_wait() ignore the write timer - it is only relevant to
write commands, it only works for the device that contains VPD, and it
might not be initialised properly at all.
Rename falcon_spi_fast_wait() to falcon_spi_wait_write(), reflecting
its use, and make it wait up to 10 ms (not 1 ms) since buffered writes
to EEPROM may take this long to complete.
Make both wait functions sleep instead of busy-waiting.
Replace wait for command completion at top of falcon_spi_cmd() with a
single poll; no command should be running when the function starts.
Correct some comments.
Signed-off-by: Ben Hutchings <bhutchings@...arflare.com>
---
drivers/net/sfc/falcon.c | 58 +++++++++++++++++++++++++++++----------------
drivers/net/sfc/mtd.c | 2 +-
drivers/net/sfc/spi.h | 2 +-
3 files changed, 39 insertions(+), 23 deletions(-)
diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index 3af361a..4b2ec12 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -1618,24 +1618,37 @@ void falcon_fini_interrupt(struct efx_nic *efx)
#define FALCON_SPI_MAX_LEN sizeof(efx_oword_t)
+static int falcon_spi_poll(struct efx_nic *efx)
+{
+ efx_oword_t reg;
+ falcon_read(efx, ®, EE_SPI_HCMD_REG_KER);
+ return EFX_OWORD_FIELD(reg, EE_SPI_HCMD_CMD_EN) ? -EBUSY : 0;
+}
+
/* Wait for SPI command completion */
static int falcon_spi_wait(struct efx_nic *efx)
{
- unsigned long timeout = jiffies + DIV_ROUND_UP(HZ, 10);
- efx_oword_t reg;
- bool cmd_en, timer_active;
+ /* Most commands will finish quickly, so we start polling at
+ * very short intervals. Sometimes the command may have to
+ * wait for VPD or expansion ROM access outside of our
+ * control, so we allow up to 100 ms. */
+ unsigned long timeout = jiffies + 1 + DIV_ROUND_UP(HZ, 10);
+ int i;
+
+ for (i = 0; i < 10; i++) {
+ if (!falcon_spi_poll(efx))
+ return 0;
+ udelay(10);
+ }
for (;;) {
- falcon_read(efx, ®, EE_SPI_HCMD_REG_KER);
- cmd_en = EFX_OWORD_FIELD(reg, EE_SPI_HCMD_CMD_EN);
- timer_active = EFX_OWORD_FIELD(reg, EE_WR_TIMER_ACTIVE);
- if (!cmd_en && !timer_active)
+ if (!falcon_spi_poll(efx))
return 0;
if (time_after_eq(jiffies, timeout)) {
EFX_ERR(efx, "timed out waiting for SPI\n");
return -ETIMEDOUT;
}
- cpu_relax();
+ schedule_timeout_uninterruptible(1);
}
}
@@ -1654,8 +1667,8 @@ int falcon_spi_cmd(const struct efx_spi_device *spi,
return -EINVAL;
BUG_ON(!mutex_is_locked(&efx->spi_lock));
- /* Check SPI not currently being accessed */
- rc = falcon_spi_wait(efx);
+ /* Check that previous command is not still running */
+ rc = falcon_spi_poll(efx);
if (rc)
return rc;
@@ -1711,26 +1724,29 @@ efx_spi_munge_command(const struct efx_spi_device *spi,
return command | (((address >> 8) & spi->munge_address) << 3);
}
-int falcon_spi_fast_wait(const struct efx_spi_device *spi)
+/* Wait up to 10 ms for buffered write completion */
+int falcon_spi_wait_write(const struct efx_spi_device *spi)
{
+ struct efx_nic *efx = spi->efx;
+ unsigned long timeout = jiffies + 1 + DIV_ROUND_UP(HZ, 100);
u8 status;
- int i, rc;
-
- /* Wait up to 1000us for flash/EEPROM to finish a fast operation. */
- for (i = 0; i < 50; i++) {
- udelay(20);
+ int rc;
+ for (;;) {
rc = falcon_spi_cmd(spi, SPI_RDSR, -1, NULL,
&status, sizeof(status));
if (rc)
return rc;
if (!(status & SPI_STATUS_NRDY))
return 0;
+ if (time_after_eq(jiffies, timeout)) {
+ EFX_ERR(efx, "SPI write timeout on device %d"
+ " last status=0x%02x\n",
+ spi->device_id, status);
+ return -ETIMEDOUT;
+ }
+ schedule_timeout_uninterruptible(1);
}
- EFX_ERR(spi->efx,
- "timed out waiting for device %d last status=0x%02x\n",
- spi->device_id, status);
- return -ETIMEDOUT;
}
int falcon_spi_read(const struct efx_spi_device *spi, loff_t start,
@@ -1784,7 +1800,7 @@ int falcon_spi_write(const struct efx_spi_device *spi, loff_t start,
if (rc)
break;
- rc = falcon_spi_fast_wait(spi);
+ rc = falcon_spi_wait_write(spi);
if (rc)
break;
diff --git a/drivers/net/sfc/mtd.c b/drivers/net/sfc/mtd.c
index a1e6c28..665cafb 100644
--- a/drivers/net/sfc/mtd.c
+++ b/drivers/net/sfc/mtd.c
@@ -76,7 +76,7 @@ static int efx_spi_unlock(const struct efx_spi_device *spi)
rc = falcon_spi_cmd(spi, SPI_WRSR, -1, &status, NULL, sizeof(status));
if (rc)
return rc;
- rc = falcon_spi_fast_wait(spi);
+ rc = falcon_spi_wait_write(spi);
if (rc)
return rc;
diff --git a/drivers/net/sfc/spi.h b/drivers/net/sfc/spi.h
index c4aca13..4e45d54 100644
--- a/drivers/net/sfc/spi.h
+++ b/drivers/net/sfc/spi.h
@@ -69,7 +69,7 @@ struct efx_spi_device {
int falcon_spi_cmd(const struct efx_spi_device *spi, unsigned int command,
int address, const void* in, void *out, unsigned int len);
-int falcon_spi_fast_wait(const struct efx_spi_device *spi);
+int falcon_spi_wait_write(const struct efx_spi_device *spi);
int falcon_spi_read(const struct efx_spi_device *spi, loff_t start,
size_t len, size_t *retlen, u8 *buffer);
int falcon_spi_write(const struct efx_spi_device *spi, loff_t start,
--
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
--
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