Anthony Foiani <t...@scrye.com> writes:
> Maybe I need to call ata_set_sata_spd as well. Can I do that before
> discovery, or should it be a part of the port_start callback? And
> if the latter, shouldn't it be handled within the ata core, instead
> of expecting each host driver to do that call?
My final version calls sata_set_spd from within the hard reset
callback for the fsl sata driver.
If there's a better place to put it, please let me know.
With this patch (and an appropriate entry in the device tree), the
machine comes up and reports:
# cd /sys/devices/e0000000.immr/e0019000.sata
# find * -name '*_spd*' -print | xargs grep .
ata2/link2/ata_link/link2/sata_spd:1.5 Gbps
ata2/link2/ata_link/link2/hw_sata_spd_limit:1.5 Gbps
ata2/link2/ata_link/link2/sata_spd_limit:1.5 Gbps
Which is what I needed to see.
Thanks for the hints!
Best regards,
Anthony Foiani
--
>From 357c96b4f31b457eca0b96147c749c21d0f4f086 Mon Sep 17 00:00:00 2001
From: Anthony Foiani <anthony.foi...@gmail.com>
Date: Wed, 8 May 2013 05:24:20 -0600
Subject: [PATCH] sata: fsl: allow device tree to limit sata speed.
There used to be an "orphan" config symbol (CONFIG_MPC8315_DS) that
would artificially limit SATA speed to generation 1 (1.5Gbps).
Since that config symbol got lost whenever any sort of configuration
was done, we instead extract the limitation from the device tree,
using a new name "sata-spd-limit".
Signed-off-by: Anthony Foiani <anthony.foi...@gmail.com>
---
.../devicetree/bindings/powerpc/fsl/board.txt | 23 ++++++++++++++++++
drivers/ata/sata_fsl.c | 28 +++++++++++-----------
2 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/board.txt
b/Documentation/devicetree/bindings/powerpc/fsl/board.txt
index 380914e..9c9fed4 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/board.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/board.txt
@@ -67,3 +67,26 @@ Example:
gpio-controller;
};
};
+
+* Maximum SATA Generation workaround
+
+Some boards advertise SATA speeds that they cannot actually achieve.
+Previously, this was dealt with via the orphaned config symbol
+CONFIG_MPC8315_DS. We now have a device tree property
+"sata-spd-limit" to control this. It should live within the "sata"
+block.
+
+Example:
+
+ sata@18000 {
+ compatible = "fsl,mpc8315-sata", "fsl,pq-sata";
+ reg = <0x18000 0x1000>;
+ cell-index = <1>;
+ interrupts = <44 0x8>;
+ interrupt-parent = <&ipic>;
+ sata-spd-limit = <1>;
+ };
+
+By default, there is no limitation; if a value is given, it indicates
+the maximum "generation" that should be negotiated. Gen 1 is 1.5Gbps,
+Gen 2 is 3.0Gbps.
diff --git a/drivers/ata/sata_fsl.c b/drivers/ata/sata_fsl.c
index d6577b9..9e3f3ec 100644
--- a/drivers/ata/sata_fsl.c
+++ b/drivers/ata/sata_fsl.c
@@ -726,20 +726,6 @@ static int sata_fsl_port_start(struct ata_port *ap)
VPRINTK("HControl = 0x%x\n", ioread32(hcr_base + HCONTROL));
VPRINTK("CHBA = 0x%x\n", ioread32(hcr_base + CHBA));
-#ifdef CONFIG_MPC8315_DS
- /*
- * Workaround for 8315DS board 3gbps link-up issue,
- * currently limit SATA port to GEN1 speed
- */
- sata_fsl_scr_read(&ap->link, SCR_CONTROL, &temp);
- temp &= ~(0xF << 4);
- temp |= (0x1 << 4);
- sata_fsl_scr_write(&ap->link, SCR_CONTROL, temp);
-
- sata_fsl_scr_read(&ap->link, SCR_CONTROL, &temp);
- dev_warn(dev, "scr_control, speed limited to %x\n", temp);
-#endif
-
return 0;
}
@@ -836,6 +822,11 @@ try_offline_again:
*/
ata_msleep(ap, 1);
+ /* if the device tree forces a speed limit, set it here. */
+ ata_link_info(link, "setting speed (in hard reset)\n");
+ DPRINTK("setting spd_limit\n");
+ sata_set_spd(link);
+
/*
* Now, bring the host controller online again, this can take time
* as PHY reset and communication establishment, 1st D2H FIS and
@@ -1444,6 +1435,15 @@ static int sata_fsl_probe(struct platform_device *ofdev)
goto error_exit_with_cleanup;
}
+ /* record speed limit if requested by device tree */
+ if (!of_property_read_u32(ofdev->dev.of_node, "sata-spd-limit",
+ &temp)) {
+ int i;
+ for (i = 0; i < SATA_FSL_MAX_PORTS; ++i)
+ host->ports[i]->link.hw_sata_spd_limit = temp;
+ dev_warn(&ofdev->dev, "speed limit set to gen %u\n", temp);
+ }
+
/* host->iomap is not used currently */
host->private_data = host_priv;
--
1.8.1.4
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
