From bbafa4668f37f5093a3ae2a8b0cbe327e24e12da Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Sun, 23 Oct 2005 19:40:22 -0700 Subject: [PATCH] [PATCH] PATCH: usb-storage: allocate separate sense buffer This patch is from Alan Stern (as560). It has been rediffed against a current tree. This patch allocates a separate buffer for usb-storage to use when auto-sensing. Up to now we have been using the sense buffer embedded in a scsi_cmnd struct, which is dangerous on hosts that (a) don't do cache-coherent DMA or (b) have DMA alignment restrictions. Signed-off-by: Alan Stern Signed-off-by: Matthew Dharm Signed-off-by: Greg Kroah-Hartman --- drivers/usb/storage/transport.c | 5 +++-- drivers/usb/storage/usb.c | 8 ++++++++ drivers/usb/storage/usb.h | 2 ++ 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c index e89e945fc4a7..7ca896a342e3 100644 --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -636,11 +636,11 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) /* use the new buffer we have */ old_request_buffer = srb->request_buffer; - srb->request_buffer = srb->sense_buffer; + srb->request_buffer = us->sensebuf; /* set the buffer length for transfer */ old_request_bufflen = srb->request_bufflen; - srb->request_bufflen = 18; + srb->request_bufflen = US_SENSE_SIZE; /* set up for no scatter-gather use */ old_sg = srb->use_sg; @@ -652,6 +652,7 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) temp_result = us->transport(us->srb, us); /* let's clean up right away */ + memcpy(srb->sense_buffer, us->sensebuf, US_SENSE_SIZE); srb->resid = old_resid; srb->request_buffer = old_request_buffer; srb->request_bufflen = old_request_bufflen; diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 92ee079d9172..eb901817b7d2 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -467,6 +467,12 @@ static int associate_dev(struct us_data *us, struct usb_interface *intf) US_DEBUGP("I/O buffer allocation failed\n"); return -ENOMEM; } + + us->sensebuf = kmalloc(US_SENSE_SIZE, GFP_KERNEL); + if (!us->sensebuf) { + US_DEBUGP("Sense buffer allocation failed\n"); + return -ENOMEM; + } return 0; } @@ -800,6 +806,8 @@ static void dissociate_dev(struct us_data *us) { US_DEBUGP("-- %s\n", __FUNCTION__); + kfree(us->sensebuf); + /* Free the device-related DMA-mapped buffers */ if (us->cr) usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr, diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h index a195adae57b6..dfa4dc71dd3e 100644 --- a/drivers/usb/storage/usb.h +++ b/drivers/usb/storage/usb.h @@ -117,6 +117,7 @@ enum { US_DO_ALL_FLAGS }; */ #define US_IOBUF_SIZE 64 /* Size of the DMA-mapped I/O buffer */ +#define US_SENSE_SIZE 18 /* Size of the autosense data buffer */ typedef int (*trans_cmnd)(struct scsi_cmnd *, struct us_data*); typedef int (*trans_reset)(struct us_data*); @@ -168,6 +169,7 @@ struct us_data { struct usb_ctrlrequest *cr; /* control requests */ struct usb_sg_request current_sg; /* scatter-gather req. */ unsigned char *iobuf; /* I/O buffer */ + unsigned char *sensebuf; /* sense data buffer */ dma_addr_t cr_dma; /* buffer DMA addresses */ dma_addr_t iobuf_dma; -- 2.30.2