Implement the SPI-GPIO delay function for busses that need speed limitation. --mb --- a/drivers/spi/spi_gpio.c +++ b/drivers/spi/spi_gpio.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -69,6 +70,7 @@ struct spi_gpio { * #define SPI_MOSI_GPIO 120 * #define SPI_SCK_GPIO 121 * #define SPI_N_CHIPSEL 4 + * #undef NEED_SPIDELAY * #include "spi_gpio.c" */ @@ -76,6 +78,7 @@ struct spi_gpio { #define DRIVER_NAME "spi_gpio" #define GENERIC_BITBANG /* vs tight inlines */ +#define NEED_SPIDELAY 1 /* all functions referencing these symbols must define pdata */ #define SPI_MISO_GPIO ((pdata)->miso) @@ -120,12 +123,20 @@ static inline int getmiso(const struct s #undef pdata /* - * NOTE: this clocks "as fast as we can". It "should" be a function of the - * requested device clock. Software overhead means we usually have trouble - * reaching even one Mbit/sec (except when we can inline bitops), so for now - * we'll just assume we never need additional per-bit slowdowns. + * NOTE: to clock "as fast as we can", set spi_device.max_speed_hz + * and spi_transfer.speed_hz to 0. + * Otherwise this is a function of the requested device clock. + * Software overhead means we usually have trouble + * reaching even one Mbit/sec (except when we can inline bitops). So on small + * embedded devices with fast SPI slaves you usually don't need a delay. */ -#define spidelay(nsecs) do {} while (0) +static inline void spidelay(unsigned nsecs) +{ +#ifdef NEED_SPIDELAY + if (unlikely(nsecs)) + ndelay(nsecs); +#endif /* NEED_SPIDELAY */ +} #define EXPAND_BITBANG_TXRX #include am/about/?h=v19.07.6'>aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/patches-3.8/007-hso-Earlier-catch-of-error-condition.patch
blob: a8a62257d2a7748faf9934407a218ef98868237e (plain) 
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From 35e57e1b49a351aa804dab6010cd46ae6112a541 Mon Sep 17 00:00:00 2001
From: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Date: Wed, 21 Aug 2013 01:43:07 -0700
Subject: [PATCH 1/2] hso: Earlier catch of error condition

There is no need to get an interface specification if we know it's the
wrong one.

Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/usb/hso.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2908,6 +2908,11 @@ static int hso_probe(struct usb_interfac
 	struct hso_shared_int *shared_int;
 	struct hso_device *tmp_dev = NULL;
 
+	if (interface->cur_altsetting->desc.bInterfaceClass != 0xFF) {
+		dev_err(&interface->dev, "Not our interface\n");
+		return -ENODEV;
+	}
+
 	if_num = interface->altsetting->desc.bInterfaceNumber;
 
 	/* Get the interface/port specification from either driver_info or from
@@ -2917,10 +2922,6 @@ static int hso_probe(struct usb_interfac
 	else
 		port_spec = hso_get_config_data(interface);
 
-	if (interface->cur_altsetting->desc.bInterfaceClass != 0xFF) {
-		dev_err(&interface->dev, "Not our interface\n");
-		return -ENODEV;
-	}
 	/* Check if we need to switch to alt interfaces prior to port
 	 * configuration */
 	if (interface->num_altsetting > 1)
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-28 05:40:12 +0000