From: Niklas Cassel <cassel@kernel.org>
To: Damien Le Moal <dlemoal@kernel.org>, Niklas Cassel <cassel@kernel.org>
Cc: Sergei Shtylyov <sergei.shtylyov@gmail.com>,
Andrey Melnikov <temnota.am@gmail.com>,
linux-ide@vger.kernel.org
Subject: [PATCH v2] ahci: print the number of implemented ports
Date: Mon, 19 Feb 2024 11:48:17 +0100 [thread overview]
Message-ID: <20240219104818.1265138-1-cassel@kernel.org> (raw)
We are currently printing the CAP.NP field.
CAP.NP is a 0's based value indicating the maximum number of ports
supported by the HBA silicon. Note that the number of ports indicated
in this field may be more than the number of ports indicated in the
PI (ports implemented) register. (See AHCI 1.3.1, section 3.1.1 -
Offset 00h: CAP – HBA Capabilities.)
Print the port_map instead, which is the value read by the PI (ports
implemented) register (after fixups).
PI (ports implemented) register is a field that has a bit set to '1'
if that specific port is implemented. This register is allowed to have
zeroes mixed with ones, i.e. a port in the middle is allowed to be
unimplemented. (See AHCI 1.3.1, section 3.1.4 - Offset 0Ch: PI – Ports
Implemented.)
Fix the libata print to only print the number of implemented ports,
instead of the theoretical number of ports supported by the HBA.
Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
Changes since V1:
-Use hweight32(). Thank you Sergei.
drivers/ata/libahci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index fca376f03c9e..ef31d234e7b6 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -2630,7 +2630,7 @@ void ahci_print_info(struct ata_host *host, const char *scc_s)
vers & 0xff,
((cap >> 8) & 0x1f) + 1,
- (cap & 0x1f) + 1,
+ hweight32(impl),
speed_s,
impl,
scc_s);
--
2.43.2
next reply other threads:[~2024-02-19 10:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-19 10:48 Niklas Cassel [this message]
2024-02-19 11:00 ` [PATCH v2] ahci: print the number of implemented ports Damien Le Moal
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240219104818.1265138-1-cassel@kernel.org \
--to=cassel@kernel.org \
--cc=dlemoal@kernel.org \
--cc=linux-ide@vger.kernel.org \
--cc=sergei.shtylyov@gmail.com \
--cc=temnota.am@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).