USB controller may access a wrong address for the dTD (endpoint transfer descriptor) and then hang. This happens a lot when doing tests with g_ether module and iperf, a tool for measuring maximum TCP and UDP bandwidth.
This hardware bug is explained in detail by errata number 2858 for i.MX23: http://cache.freescale.com/files/dsp/doc/errata/IMX23CE.pdf mv_udc_core fixes this bug by commit daec765. There still may be unfixed drivers. Signed-off-by: Christoph Fritz <chf.fr...@googlemail.com> Signed-off-by: Christian Hemp <c.h...@phytec.de> --- drivers/usb/gadget/fsl_udc_core.c | 22 ++++++++++++++++++++++ drivers/usb/gadget/fsl_usb2_udc.h | 6 ++++++ 2 files changed, 28 insertions(+), 0 deletions(-) diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c index 55abfb6..f9bfafd 100644 --- a/drivers/usb/gadget/fsl_udc_core.c +++ b/drivers/usb/gadget/fsl_udc_core.c @@ -65,6 +65,9 @@ static struct usb_sys_interface *usb_sys_regs; /* it is initialized in probe() */ static struct fsl_udc *udc_controller = NULL; +#ifdef POSTPONE_FREE_LAST_DTD +static struct ep_td_struct *last_free_td; +#endif static const struct usb_endpoint_descriptor fsl_ep0_desc = { .bLength = USB_DT_ENDPOINT_SIZE, @@ -180,8 +183,18 @@ static void done(struct fsl_ep *ep, struct fsl_req *req, int status) curr_td = next_td; if (j != req->dtd_count - 1) { next_td = curr_td->next_td_virt; +#ifdef POSTPONE_FREE_LAST_DTD + dma_pool_free(udc->td_pool, curr_td, curr_td->td_dma); + } else { + if (last_free_td != NULL) + dma_pool_free(udc->td_pool, last_free_td, + last_free_td->td_dma); + last_free_td = curr_td; + } +#else } dma_pool_free(udc->td_pool, curr_td, curr_td->td_dma); +#endif } if (req->mapped) { @@ -2579,6 +2592,10 @@ static int __init fsl_udc_probe(struct platform_device *pdev) goto err_unregister; } +#ifdef POSTPONE_FREE_LAST_DTD + last_free_td = NULL; +#endif + ret = usb_add_gadget_udc(&pdev->dev, &udc_controller->gadget); if (ret) goto err_del_udc; @@ -2633,6 +2650,11 @@ static int __exit fsl_udc_remove(struct platform_device *pdev) kfree(udc_controller->status_req); kfree(udc_controller->eps); +#ifdef POSTPONE_FREE_LAST_DTD + if (last_free_td != NULL) + dma_pool_free(udc_controller->td_pool, last_free_td, + last_free_td->td_dma); +#endif dma_pool_destroy(udc_controller->td_pool); free_irq(udc_controller->irq, udc_controller); iounmap(dr_regs); diff --git a/drivers/usb/gadget/fsl_usb2_udc.h b/drivers/usb/gadget/fsl_usb2_udc.h index e651469..03ae07f 100644 --- a/drivers/usb/gadget/fsl_usb2_udc.h +++ b/drivers/usb/gadget/fsl_usb2_udc.h @@ -4,6 +4,12 @@ #ifndef __FSL_USB2_UDC_H #define __FSL_USB2_UDC_H +#if defined CONFIG_ARCH_MX51 || defined CONFIG_SOC_IMX35 +#define POSTPONE_FREE_LAST_DTD +#else +#undef POSTPONE_FREE_LAST_DTD +#endif + /* ### define USB registers here */ #define USB_MAX_CTRL_PAYLOAD 64 -- 1.7.2.5 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
