Re: [BUG] 2.6.24-git usb reset problems

Geert Uytterhoeven
2008-01-30T10:28:08Z

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On Tue, 29 Jan 2008, Jens Axboe wrote:
> On Tue, Jan 29 2008, Jens Axboe wrote:
> > On Tue, Jan 29 2008, James Bottomley wrote:
> > > On Tue, 2008-01-29 at 11:10 -0800, Matthew Dharm wrote:
> > > > For some reason, usb_sg_init is boned during auto-sense.
> > >
> > > OK, that's implicating the scsi_eh_prep_cmnd() in the auto sense
> > > code ... that was also an update in 2.6.24
> >
> > yeah, already found the bug - it's assuming ->request_buffer holds the
> > sglist, oops. Preparing a fix.
>
> ok here goes, this saves and restores the sg table correctly. it also
> fixes the usb bug for me.

I can confirm this patch fixes the errors I was seeing with current
linux-2.6.git for the USB memory card readers in a Dell TFT connected to a PS3.

> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
> index 547e85a..12770ef 100644
> --- a/drivers/scsi/scsi_error.c
> +++ b/drivers/scsi/scsi_error.c
> @@ -622,13 +622,15 @@ void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
> ses->use_sg = scmd->use_sg;
> ses->resid = scmd->resid;
> ses->result = scmd->result;
> + memcpy(&ses->sense_sgl, &scmd->sg_table, sizeof(ses->sense_sgl));
>
> if (sense_bytes) {
> scmd->request_bufflen = min_t(unsigned,
> SCSI_SENSE_BUFFERSIZE, sense_bytes);
> sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
> scmd->request_bufflen);
> - scmd->request_buffer = &ses->sense_sgl;
> + scmd->sg_table.sgl = &ses->sense_sgl;
> + scmd->sg_table.nents = scmd->sg_table.orig_nents = 1;
> scmd->sc_data_direction = DMA_FROM_DEVICE;
> scmd->use_sg = 1;
> memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
> @@ -679,6 +681,7 @@ void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
> scmd->request_bufflen = ses->bufflen;
> scmd->request_buffer = ses->buffer;
> scmd->use_sg = ses->use_sg;
> + memcpy(&scmd->sg_table, &ses->sg_table, sizeof(scmd->sg_table));
> scmd->resid = ses->resid;
> scmd->result = ses->result;
> }
> diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
> index d21b891..d43dc83 100644
> --- a/include/scsi/scsi_eh.h
> +++ b/include/scsi/scsi_eh.h
> @@ -75,6 +75,7 @@ struct scsi_eh_save {
>
> void *buffer;
> unsigned bufflen;
> + struct sg_table sg_table;
> unsigned short use_sg;
> int resid;
>

With kind regards,

Geert Uytterhoeven
Software Architect

Sony Network and Software Technology Center Europe
The Corporate Village · Da Vincilaan 7-D1 · B-1935 Zaventem · Belgium

Phone: +32 (0)2 700 8453
Fax: +32 (0)2 700 8622
E-mail: Geert.Uytterhoeven@sonycom.com
Internet: http://www.sony-europe.com/

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