| Message ID | 1377041578-9149-1-git-send-email-joelf@ti.com |
|---|---|
| State | Superseded |
| Delegated to: | Marek Vasut |
| Headers | show |
Dear Joel Fernandes, > As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned > on 4 byte boundaray causing data aborts in eth_setup -> conf_buf > during dhcp boot over usb_ether. Fix the issue my aligning control_req > buffer to 4-byte boundary. > > Tested on am335x_evm platform (beaglebone). > Applies on 2013.10-rc1 branch. > > Cc: Tom Rini <trini@ti.com> > Signed-off-by: Joel Fernandes <joelf@ti.com> Please keep me in the CC next time. > --- > drivers/usb/gadget/ether.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c > index 579893c..251d7b2 100644 > --- a/drivers/usb/gadget/ether.c > +++ b/drivers/usb/gadget/ether.c > @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { > }; > > /*======================================================================== > ====*/ -static u8 control_req[USB_BUFSIZ]; > +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4))); Please make this cacheline aligned, so we get rid of bounce buffering of the requests on stupid hardware. > #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) > static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here. > #endif Best regards, Marek Vasut
On 08/27/2013 08:52 AM, Marek Vasut wrote: > Dear Joel Fernandes, > >> As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned >> on 4 byte boundaray causing data aborts in eth_setup -> conf_buf >> during dhcp boot over usb_ether. Fix the issue my aligning control_req >> buffer to 4-byte boundary. >> >> Tested on am335x_evm platform (beaglebone). >> Applies on 2013.10-rc1 branch. >> >> Cc: Tom Rini <trini@ti.com> >> Signed-off-by: Joel Fernandes <joelf@ti.com> > > Please keep me in the CC next time. Ok. >> --- >> drivers/usb/gadget/ether.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c >> index 579893c..251d7b2 100644 >> --- a/drivers/usb/gadget/ether.c >> +++ b/drivers/usb/gadget/ether.c >> @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { >> }; >> >> /*======================================================================== >> ====*/ -static u8 control_req[USB_BUFSIZ]; >> +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4))); > > Please make this cacheline aligned, so we get rid of bounce buffering of the > requests on stupid hardware. >> #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) >> static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); > > This could also use fixing, but the STATUS_BYTECOUNT would need to be up-aligned > as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in both cases here. Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining a new DEFINE_CACHE_ALIGN_BUFFER macro? Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its needed to be up-aligned? Regards, -Joel > >> #endif > > Best regards, > Marek Vasut >
Dear Joel Fernandes, > On 08/27/2013 08:52 AM, Marek Vasut wrote: > > Dear Joel Fernandes, > > > >> As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned > >> on 4 byte boundaray causing data aborts in eth_setup -> conf_buf > >> during dhcp boot over usb_ether. Fix the issue my aligning control_req > >> buffer to 4-byte boundary. > >> > >> Tested on am335x_evm platform (beaglebone). > >> Applies on 2013.10-rc1 branch. > >> > >> Cc: Tom Rini <trini@ti.com> > >> Signed-off-by: Joel Fernandes <joelf@ti.com> > > > > Please keep me in the CC next time. > > Ok. > > >> --- > >> > >> drivers/usb/gadget/ether.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c > >> index 579893c..251d7b2 100644 > >> --- a/drivers/usb/gadget/ether.c > >> +++ b/drivers/usb/gadget/ether.c > >> @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { > >> > >> }; > >> > >> /*===================================================================== > >> === > >> > >> ====*/ -static u8 control_req[USB_BUFSIZ]; > >> +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4))); > > > > Please make this cacheline aligned, so we get rid of bounce buffering of > > the requests on stupid hardware. > > > >> #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) > >> static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); > > > > This could also use fixing, but the STATUS_BYTECOUNT would need to be > > up-aligned as well then. Some DEFINE_CACHE_ALIGN_BUFFER might help in > > both cases here. > > Ok, how about __aligned(CONFIG_SYS_CACHELINE_SIZE) instead of defining > a new DEFINE_CACHE_ALIGN_BUFFER macro? THis is already defined and used throughout the USB code, check include/common.h IIRC. > Can you explain what you meant by STATUS_BYTECOUNT up-aligned and why its > needed to be up-aligned? it's 16 bytes now, no? Up-align it to cacheline size. Best regards, Marek Vasut
diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c index 579893c..251d7b2 100644 --- a/drivers/usb/gadget/ether.c +++ b/drivers/usb/gadget/ether.c @@ -849,7 +849,7 @@ static struct usb_gadget_strings stringtab = { }; /*============================================================================*/ -static u8 control_req[USB_BUFSIZ]; +static u8 control_req[USB_BUFSIZ] __attribute__ ((aligned(4))); #if defined(CONFIG_USB_ETH_CDC) || defined(CONFIG_USB_ETH_RNDIS) static u8 status_req[STATUS_BYTECOUNT] __attribute__ ((aligned(4))); #endif
As seen on GCC 4.6 Linaro compiler, control_req buffer is not aligned on 4 byte boundaray causing data aborts in eth_setup -> conf_buf during dhcp boot over usb_ether. Fix the issue my aligning control_req buffer to 4-byte boundary. Tested on am335x_evm platform (beaglebone). Applies on 2013.10-rc1 branch. Cc: Tom Rini <trini@ti.com> Signed-off-by: Joel Fernandes <joelf@ti.com> --- drivers/usb/gadget/ether.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)