path: root/arch/arm/mach-pxa/idp.c
diff options
authorRussell King <rmk+kernel@armlinux.org.uk>2016-08-27 17:33:03 +0100
committerDavid S. Miller <davem@davemloft.net>2016-08-28 23:44:55 -0400
commit2fb04fdf30192ff1e2b5834e9b7745889ea8bbcb (patch)
tree2a05f0268408c60503c31ecc41153ff1bec04290 /arch/arm/mach-pxa/idp.c
parentDocumentation: networking: dsa: Remove platform device TODO (diff)
net: smc91x: fix SMC accesses
Commit b70661c70830 ("net: smc91x: use run-time configuration on all ARM machines") broke some ARM platforms through several mistakes. Firstly, the access size must correspond to the following rule: (a) at least one of 16-bit or 8-bit access size must be supported (b) 32-bit accesses are optional, and may be enabled in addition to the above. Secondly, it provides no emulation of 16-bit accesses, instead blindly making 16-bit accesses even when the platform specifies that only 8-bit is supported. Reorganise smc91x.h so we can make use of the existing 16-bit access emulation already provided - if 16-bit accesses are supported, use 16-bit accesses directly, otherwise if 8-bit accesses are supported, use the provided 16-bit access emulation. If neither, BUG(). This exactly reflects the driver behaviour prior to the commit being fixed. Since the conversion incorrectly cut down the available access sizes on several platforms, we also need to go through every platform and fix up the overly-restrictive access size: Arnd assumed that if a platform can perform 32-bit, 16-bit and 8-bit accesses, then only a 32-bit access size needed to be specified - not so, all available access sizes must be specified. This likely fixes some performance regressions in doing this: if a platform does not support 8-bit accesses, 8-bit accesses have been emulated by performing a 16-bit read-modify-write access. Tested on the Intel Assabet/Neponset platform, which supports only 8-bit accesses, which was broken by the original commit. Fixes: b70661c70830 ("net: smc91x: use run-time configuration on all ARM machines") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/arm/mach-pxa/idp.c')
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm/mach-pxa/idp.c b/arch/arm/mach-pxa/idp.c
index c410d84b243d..66070acaa888 100644
--- a/arch/arm/mach-pxa/idp.c
+++ b/arch/arm/mach-pxa/idp.c
@@ -83,7 +83,8 @@ static struct resource smc91x_resources[] = {
static struct smc91x_platdata smc91x_platdata = {
- .flags = SMC91X_USE_32BIT | SMC91X_USE_DMA | SMC91X_NOWAIT,
+ .flags = SMC91X_USE_8BIT | SMC91X_USE_16BIT | SMC91X_USE_32BIT |
static struct platform_device smc91x_device = {