Re-Sending: Christoph, The e-mail I sent out on Oct. 31st was bounced back, I re-send it again. I see that scsi_scan_host_selected is in scsi_priv.h and currently is not used by any other driver. The scsi_priv.h is not part of the include dir (/include/scsi). One of the major Linux distro's don't even include this file in /usr/src/kernels. Also it looks like at this time this function may not be available (not exported?) for driver modules to use. Even if I include scsi_priv.h I get "unknown symbol" for this function while loading. May be in the long run we can solve all these issues to call scsi_scan_host_selected. However, the current implementation works fine and has been tested by LSI and others. This implementation doesn't break any protocol nor does it adversely affect any driver functionality. In a future update soon I will modify the comment on proc/scsi and remove the extra braces you have pointed out. Please accept the current implementation/patches. Regards, Bo Yang ------------------------------------------------------------------------ ------------------------ From: Yang, Bo Sent: Wednesday, October 31, 2007 9:46 AM To: Christoph Hellwig Cc: linux-scsi@xxxxxxxxxxxxxxx; James.Bottomley@xxxxxxxxxxxx; akpm@xxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Patro, Sumant; Kolli, Neela Subject: RE: PATCH [2/8] scsi: megaraid_sas - add module param fast_load Christoph, I see that scsi_scan_host_selected is in scsi_priv.h and currently is not used by any other driver. The scsi_priv.h is not part of the include dir (/include/scsi). One of the major Linux distro's don't even include this file in /usr/src/kernels. Also it looks like at this time this function may not be available (not exported?) for driver modules to use. Even if I include scsi_priv.h I get "unknown symbol" for this function while loading. May be in the long run we can solve all these issues to call scsi_scan_host_selected. However, the current implementation works fine and has been tested by LSI and others. This implementation doesn't break any protocol nor does it adversely affect any driver functionality. In a future update soon I will modify the comment on proc/scsi and remove the extra braces you have pointed out. Please accept the current implementation/patches. Regards, Bo Yang -----Original Message----- From: Christoph Hellwig [mailto:hch@xxxxxxxxxxxxx] Sent: Tuesday, October 30, 2007 1:37 PM To: Yang, Bo Cc: linux-scsi@xxxxxxxxxxxxxxx; James.Bottomley@xxxxxxxxxxxx; akpm@xxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Patro, Sumant Subject: Re: PATCH [2/8] scsi: megaraid_sas - add module param fast_load On Mon, Oct 01, 2007 at 11:46:51AM -0400, bo yang wrote: > +/* > + * Fast driver load option, skip scanning for physical devices during > + * load. This would result in physical devices being skipped during > + * driver load time. These can be later added though, > + * using /proc/scsi/scsi > + */ /proc/scsi/scsi is deprecated, so please don't recommend it here. The proper way is the scan attribute of the scsi host. > +static unsigned int fast_load; > +module_param_named(fast_load, fast_load, int, 0); > +MODULE_PARM_DESC(fast_load, > + "megasas: Faster loading of the driver, skips physical devices! "\ > + "(default = 0)"); This should show up in sysfs. > +static struct megasas_instance *megasas_lookup_instance(u16 host_no) > +{ > + int i; > + > + for (i = 0; i < megasas_mgmt_info.max_index; i++) { > + if ((megasas_mgmt_info.instance[i]) && > + (megasas_mgmt_info.instance[i]->host->host_no > + == host_no)) no need for the braces here. This should be: if (megasas_mgmt_info.instance[i] && megasas_mgmt_info.instance[i]->host->host_no == host_no) > +static int megasas_slave_alloc(struct scsi_device *sdev) { > + struct megasas_instance *instance; > + int tmp_fastload = fast_load; > + > + instance = megasas_lookup_instance(sdev->host->host_no); > + > + if (tmp_fastload && sdev->channel < MEGASAS_MAX_PD_CHANNELS) { > + if ((sdev->id == MEGASAS_MAX_DEV_PER_CHANNEL -1) && > + (sdev->channel == MEGASAS_MAX_PD_CHANNELS - 1)) { > + > + /* > + * If fast load option was set and scan for last device is > + * over, reset the fast_load flag so that during a possible > + * next scan, devices can be made available > + */ > + fast_load = 0; > + } > + return -ENXIO; > + } > + > + return 0; > +} This is a rather complicated and fragile way to implement this feature. I'd recomment to change the call to scsi_scan_host in megasas_io_attach to something like: if (fast_load) { int channel; for (channel = 0; channel < MEGASAS_MAX_PD_CHANNELS; channel++) { scsi_scan_host_selected(host, channel, SCAN_WILD_CARD, SCAN_WILD_CARD, 0); } } else { scsi_scan_host(host); } - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
