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Thread deadlock in high level disk driver?
- From: "Davy Wouters Atos \(Gmail\)" <davy dot wouters dot atos at gmail dot com>
- To: <ecos-discuss at ecos dot sourceware dot org>
- Date: Wed, 1 Dec 2010 10:45:39 +0100
- Subject: [ECOS] Thread deadlock in high level disk driver?
Hello everyone,
I have found something strange in de High level Disk Driver
(/packages/io/disk/current/src/disk.c).
I am using this to access the mmc_spi driver and an spi driver I wrote
myself.
When something goes wrong in the mmc_spi or spi driver, a deadlock occurs
leaving the disk controller busy.
The functions disk_bread and disk_bwrite contains 'goto done;' statements.
In the case these goto statements
are executed (probably something wrong in low level driver), the ctrl->busy
is not cleared to false and any subsequent
calls to the disk driver result in a cyg_drv_cond_wait. (putting the thread
it's in to sleep)
For now i have patched to code as follows below to prevent this from
happening.
Maybe this code is intended to lock the disk controller when an error
occurs?
Any comments anyone?
Tnx,
Kind regards,
Davy Wouters
*** disk.c Wed Dec 1 10:38:15 2010
--- _disk.c Wed Dec 1 10:37:47 2010
***************
*** 560,570 ****
--- 560,576 ----
cyg_drv_dsr_unlock();
if (ENOERR != res)
+ {
+ ctlr->busy = false;
+ cyg_drv_cond_signal( &ctlr->queue );
goto done;
+ }
if (!info->connected)
{
res = -EINVAL;
+ ctlr->busy = false;
+ cyg_drv_cond_signal( &ctlr->queue );
goto done;
}
***************
*** 636,642 ****
if (pos > last)
{
res = -EIO;
! goto done;
}
if( tfr > info->ident.max_transfer )
--- 642,648 ----
if (pos > last)
{
res = -EIO;
! break;
}
if( tfr > info->ident.max_transfer )
***************
*** 664,674 ****
--- 670,686 ----
cyg_drv_dsr_unlock();
if (ENOERR != res)
+ {
+ ctlr->busy = false;
+ cyg_drv_cond_signal( &ctlr->queue );
goto done;
+ }
if (!info->connected)
+ ctlr->busy = false;
+ cyg_drv_cond_signal( &ctlr->queue );
goto done;
}
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