| Message ID | 1303541890-14528-1-git-send-email-jipeng2005@gmail.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
On 04/23/2011 02:58 AM, Jian Peng wrote: > At the end of section 10.1 of AHCI spec (rev 1.3), it states > > Software shall not set PxCMD.ST to 1 until it is determined that > a functoinal device is present on the port as determined by > PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h > > Even though most AHCI host controller works without this check, > specific controller will fail under this condition. > > Signed-off-by: Jian Peng<jipeng2005@gmail.com> > --- > drivers/ata/libahci.c | 21 +++++++++++++++++++++ > 1 files changed, 21 insertions(+), 0 deletions(-) > > diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c > index 26d4523..83ed544 100644 > --- a/drivers/ata/libahci.c > +++ b/drivers/ata/libahci.c > @@ -539,6 +539,27 @@ void ahci_start_engine(struct ata_port *ap) > { > void __iomem *port_mmio = ahci_port_base(ap); > u32 tmp; > + u8 status; > + > + status = readl(port_mmio + PORT_TFDATA)& 0xFF; > + > + /* > + * At end of section 10.1 of AHCI spec (rev 1.3), it states > + * Software shall not set PxCMD.ST to 1 until it is determined > + * that a functoinal device is present on the port as determined by > + * PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h > + * > + * Even though most AHCI host controllers work without this check, > + * specific controller will fail under this condition > + */ > + if (status& (ATA_BUSY | ATA_DRQ)) > + return; > + else { > + ahci_scr_read(&ap->link, SCR_STATUS,&tmp); > + > + if ((tmp& 0xf) != 0x3) > + return; > + } Looks good, I'll get this queued up... -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Apr 23, 2011 at 8:58 AM, Jian Peng <jipeng2005@gmail.com> wrote: > At the end of section 10.1 of AHCI spec (rev 1.3), it states > > Software shall not set PxCMD.ST to 1 until it is determined that > a functoinal device is present on the port as determined by > PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h > > Even though most AHCI host controller works without this check, > specific controller will fail under this condition. > > Signed-off-by: Jian Peng <jipeng2005@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Thanks.
Hello. On 23-04-2011 10:58, Jian Peng wrote: > At the end of section 10.1 of AHCI spec (rev 1.3), it states > Software shall not set PxCMD.ST to 1 until it is determined that > a functoinal device is present on the port as determined by > PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h > Even though most AHCI host controller works without this check, "Most" requires plural noun, no? > specific controller will fail under this condition. > Signed-off-by: Jian Peng<jipeng2005@gmail.com> [...] > diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c > index 26d4523..83ed544 100644 > --- a/drivers/ata/libahci.c > +++ b/drivers/ata/libahci.c > @@ -539,6 +539,27 @@ void ahci_start_engine(struct ata_port *ap) > { > void __iomem *port_mmio = ahci_port_base(ap); > u32 tmp; > + u8 status; > + > + status = readl(port_mmio + PORT_TFDATA) & 0xFF; Masking is not necessary. > + > + /* > + * At end of section 10.1 of AHCI spec (rev 1.3), it states > + * Software shall not set PxCMD.ST to 1 until it is determined > + * that a functoinal device is present on the port as determined by > + * PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h > + * > + * Even though most AHCI host controllers work without this check, Same about grammar here. > + * specific controller will fail under this condition > + */ > + if (status& (ATA_BUSY | ATA_DRQ)) > + return; > + else { {} should be used on both branches, according to CodingStyle. WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index 26d4523..83ed544 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -539,6 +539,27 @@ void ahci_start_engine(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); u32 tmp; + u8 status; + + status = readl(port_mmio + PORT_TFDATA) & 0xFF; + + /* + * At end of section 10.1 of AHCI spec (rev 1.3), it states + * Software shall not set PxCMD.ST to 1 until it is determined + * that a functoinal device is present on the port as determined by + * PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h + * + * Even though most AHCI host controllers work without this check, + * specific controller will fail under this condition + */ + if (status & (ATA_BUSY | ATA_DRQ)) + return; + else { + ahci_scr_read(&ap->link, SCR_STATUS, &tmp); + + if ((tmp & 0xf) != 0x3) + return; + } /* start DMA */ tmp = readl(port_mmio + PORT_CMD);
At the end of section 10.1 of AHCI spec (rev 1.3), it states Software shall not set PxCMD.ST to 1 until it is determined that a functoinal device is present on the port as determined by PxTFD.STS.BSY=0, PxTFD.STS.DRQ=0 and PxSSTS.DET=3h Even though most AHCI host controller works without this check, specific controller will fail under this condition. Signed-off-by: Jian Peng <jipeng2005@gmail.com> --- drivers/ata/libahci.c | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-)