From 79940cf8759558d55b597e27353f6521516aa7ac Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 7 Apr 2015 11:27:10 +0200 Subject: [PATCH] greybus: es1: fix DMA-buffer on stack A stack-allocated buffer is not generally DMA-able and must not be used for USB control transfers. Note that the memset and extra buffer byte were redundant as no more than the bytes actually transferred was ever added to the fifo. Signed-off-by: Johan Hovold Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/es1.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/staging/greybus/es1.c b/drivers/staging/greybus/es1.c index 7f7e2fdc094f..f2c1cde96221 100644 --- a/drivers/staging/greybus/es1.c +++ b/drivers/staging/greybus/es1.c @@ -454,14 +454,13 @@ static void cport_out_callback(struct urb *urb) free_urb(es1, urb); } -static void apb1_log_get(struct es1_ap_dev *es1) +#define APB1_LOG_MSG_SIZE 64 +static void apb1_log_get(struct es1_ap_dev *es1, char *buf) { - char buf[65]; int retval; /* SVC messages go down our control pipe */ do { - memset(buf, 0, 65); retval = usb_control_msg(es1->usb_dev, usb_rcvctrlpipe(es1->usb_dev, es1->control_endpoint), @@ -469,7 +468,7 @@ static void apb1_log_get(struct es1_ap_dev *es1) USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE, 0x00, 0x00, buf, - 64, + APB1_LOG_MSG_SIZE, ES1_TIMEOUT); if (retval > 0) kfifo_in(&apb1_log_fifo, buf, retval); @@ -478,10 +477,20 @@ static void apb1_log_get(struct es1_ap_dev *es1) static int apb1_log_poll(void *data) { + struct es1_ap_dev *es1 = data; + char *buf; + + buf = kmalloc(APB1_LOG_MSG_SIZE, GFP_KERNEL); + if (!buf) + return -ENOMEM; + while (!kthread_should_stop()) { msleep(1000); - apb1_log_get((struct es1_ap_dev *)data); + apb1_log_get(es1, buf); } + + kfree(buf); + return 0; } -- 2.11.0