>-----Original Message----- >From: Chen Peter-B29397 >Sent: Wednesday, February 15, 2012 3:12 PM >To: Li Yang-R58472; balbi@xxxxxx >Cc: linux-usb@xxxxxxxxxxxxxxx >Subject: RE: [PATCH 1/1] usb: fsl_udc_core: Fix scheduling while atomic >dump message > > >> >> >> >> >> >The reason of above dump message is calling dma_poll_alloc with >> >> >> >can- schedule mem_flags at interrupt context. Changing >> >> >> >mem_flags from GFP_KERNEL to GFP_ATOMIC fix this problem. >> >> >> >> >> >> Thanks for the patch. But I think the proper way to fix this is >> >> >> to use the gfp_flags parameter passed by fsl_ep_queue(). >> >> >> >> >> >Hi Leo, current allocate dtd descriptor code are all at atomic >> context. >> >> >> >> Most of the usb_ep_queue() are using GFP_ATOMIC, but there are a >> >> few using GFP_KERNEL. For example start_transfer() in file_storage.c. >> >> >> >It is in spin_lock_irqsave/spin_unlock_irqrestore. >> >> You are quite right. But on a second thought, it seems to me that the >> fsl_req_to_dtd() doesn't need to hold the lock while fsl_queue_td() does. >> Might need to change that also? >> >Correct, we don't need to protect current struct usb_request, but need to >protect hardware visit at fsl_queue_td(). > >So, is it ok I post v2 patch by adding gfp_flags to fsl_queue_td, and move >lock from beginning of fsl_req_to_dtd to beginning of fsl_queue_td? Yes. Please. - Leo -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
