lkml.org 
[lkml]   [2016]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 1/2] usb: musb: Fix DMA for host mode
From
Date
On 02/02/2016 04:24 PM, Sergei Shtylyov wrote:

>> From: Cristian Birsan <cristian.birsan@microchip.com>
>>
>> Commit ac33cdb166811223cc (usb: musb: Remove ifdefs for musb_host_rx in
>> musb_host.c part5) introduces a problem setting DMA host mode.
>
> scripts/checkpatch.pl now enforces certain commit citing style, yours
> doesn't quite match it.
>
>> This fixes the done condition that advances the musb schedule. Without this
>> patch the the msub_advance_schedule() is called immediately after receiving an
>> endpoint rx interrupt without waiting for the dma transfer to complete. As a
>> consequence when the dma complete interrupt arrives the in_qh member of hw_ep
>> is already null an the musb_host_rx() exits on !urb error case.
>>
>> Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
>> Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
>> ---
>> drivers/usb/musb/musb_host.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> index 795a45b..3fdc99b 100644
>> --- a/drivers/usb/musb/musb_host.c
>> +++ b/drivers/usb/musb/musb_host.c
>> @@ -1825,6 +1825,7 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> u16 rx_csr, val;
>> bool iso_err = false;
>> bool done = false;
>> + int ret;
>> u32 status;
>> struct dma_channel *dma;
>> unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
>> @@ -2003,10 +2004,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> qh->offset,
>> urb->transfer_buffer_length);
>>
>> - done = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh,
>> + ret = musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh,
>> urb, xfer_len,
>> iso_err);
>> - if (done)
>> + if (ret)
>
> Hm, does that really fix anything?

Looking again, I got the idea. However, there's no dire need for the new
variable...
(Handling Inventra and CPPI 4.1 DMA in the same code looks fishy. Too bad
I wasn't able to push the CPPI 4.1 drivers myself.)

MBR, Sergei

\
 
 \ /
  Last update: 2016-02-04 18:21    [W:0.064 / U:0.620 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site